: 2001 Northstar - Head Gaskets blown or not?? I'm stumped!!



hms200
01-10-11, 03:36 AM
Hi gents...I purchased 2001 Eldorado that was diagnosed by Caddy dealship to have blown HG's. I've done a bettery of tests before breaking into the engine attempting to validate the blown HG's...but no definitive evidence yet...HELP!!

What I think I know:
1. Definitely overheating
2. Excessive back pressure boils coolant from tank
3. Upper & Lower hoses hot and under pressure
4. Water Pump does NOT leak
5. Conducted block test (blue chemical test) multiple times correctly using reliable test ket - zero evidence of exhaust in coolant (tested 4 times)
6. No exhaust smell in coolant tank that I can detect
7. Zero white smoke from tailpipe
8. No water from tailpipe once it reaches normal operating temp (after initial condensation is gone)
9. No funky coolant smell in exhaust
10. Conducted compression test - "wet test" results as follows (dry tests were a bit lower but equally consistant):

Front Bank (Left to Right)
183 - 192 -191 - 180

Back Bank (Left to Right)
184 - 196 - 189 - 205

Ok...so unless somebody spots anything I'm missing, I'm not getting definitive evidence of blown HG's at this stage. Compression appears good (I think?), within reasonable spec and all cylinders within spec range of each other (within 10%)...yes? As I understand it, the Northstar CAN pass compression test but still have blown HG's due to nature of high compression engine under normal operating condition/load. Right? But other tests don't give me evidence either...so I'm reslly stumped!!

What are the odds that I have radiator blockage or a failed thermostat rather than blown HG's? Odds seem slim to me from all I've read about widespead failure of head bolts, but evidence sure is pointing away from HG's with all I see so far.

So all you really smart gents please chime in with your thoughts, questions, ideas.

Many thanks - Howard

hms200
01-10-11, 04:48 AM
I should also add to the "What I do know" section...

I've also confirmed there is NO WATER in the oil and all spark plugs were clean; looked completely normal. There was no evidence on the plugs of burning or blowing any coolant. - Howard

Ranger
01-10-11, 12:57 PM
A compression test won't tell you anything regarding a head gasket. A leak down test is what you need. Northstars won't put coolant in the oil so forget that as an indicator. How about the purge line? Have you verified that it is open and flows coolant? A radiator blockage or a failed thermostat is not common, but worth checking out. The multiple negative block tests are confusing. I wonder how the dealer diagnosed it?

hms200
01-10-11, 02:31 PM
Thx for your reply Ranger...

Yes, I read much data indicating that compression test isn't proof if it passes, but can at times prove things if it fails. Also plug condition is suppose to be a good potential indicator, but as I said, they were all very clean.

I'm confused as well on block test giving me no positive results. That's suppose to be one of the most sure tests of blown HG's, and especially given the degree of back pressure or boiling that happens in very short order. I have no clue how dealership diagnosed it. They performed that diagnosis for prior owner, whereby he then sold me the car after getting the grim news and quote for the HG repair.

I have no further test gear at my disposal, so a leak down test (is that pressure testing the cooling system?) I'm not able to perform.

I know nothing about the purge line sir...where it is, what to look for and where a blockage might be in the line. I'll try researching that and if you can provide more info I'd greatly appreciate it. It goes from where to where and how best to confirm blockage and clear if present?

I agree that radiator/thermostat are both stretches...seldom the cause if neither are leaking or in obvious poor condition. That's why I'm hesitating before running out to get replacement parts for either. Both seem to be first things many shops change out on their way to determining HG's and I don't want to follow that same monkey trail blindly without more evidence. But, I also don't want to simply dive into the engine on just the unqualified word of a prior dealership diagnosis without securing some reasonable supporting evidence of my own.

More info...

I can make the engine overheat very quickly and easily with it simply sitting in my garage. With coolant level topped off I simply have to rev the engine up/down to ~2500 rpm's for maybe 5 minutes and then temp will start clocking past mid point. I've read where many folks can drive-drive-drive without overheating so long as they avoid grades and severe speeds. For how fast mine heats up I would have expected major/clear results from troubleshooting...but nope. The cooling fans DO work as they should by the way.

RippyPartsDept
01-10-11, 03:04 PM
also, w/ a blown HG you'll be losing coolant so if the system isn't losing any coolant there's reason to believe that something else is going on.... that said, if it continues to overheat then there's a good chance that the HG's will blow... the hotter the block gets the more likely those head bolts will pull out of the block

hms200
01-10-11, 03:52 PM
Thanks Rippy...

I'm not driving vehicle at all since purchase from gentleman that received the grim news from dealership. It's garaged with hood up and me sitting in engine compartment trying to figure out this mystery. :)

As for losing coolant...that is happening, but only as a direct result of boil over from the tank. It overflows from tube and I can hear/feel the boiling when that happening. With cap off then it simply surges up and over like an angry volcano. No leaks anywhere else in the cooling system. - HMS

zonie77
01-10-11, 04:08 PM
Bad pressure cap, stuck or missing thermostat, and a plugged purge line are all possibilities. Usually bad HG's cause little pressure on the top hose.

On initial HG failure the block test can be "iffy" as there is usually some pressure on the gaskets but yours sounds like it should be giving a positive indication.

I would usually advise someone to do the block test before too much else (only the 3 things I listed) but in your case it might be worth flushing the radiator, possibly a lot of stop leak has been added.

Since you said the WP is not leaking I assume the belt is good?.?.

Submariner409
01-10-11, 05:15 PM
yeah, that ^^^^ W/P belt/tensioner/pulley is suspect. On the driver's end of the front intake cam.

The constant bleed purge line runs from a hollow bolt/nipple at the rear of the thermostat housing and goes to a nipple on the top side of the coolant reservoir. That hollow bolt is one of the clog culprits - a proper sized drill and care is what it takes.......coolant should constantly flow into the top side of the reservoir - remove the line, hold it in the open filler neck, have an assistant start the engine, and it should show a steady stream.

Fans go to slow at 224 and fast at 236, and they run all the time in slow if any A/C mode is called for.

Open these and study them...............

hms200
01-10-11, 05:33 PM
Thx Zonie...

Just confirmed no blockage in purge tube.

Yes, water pump belt is fine.

The block test was very first troubleshooting I performed. Expected to get immediate positive results, but I was surprised...thus my reason for repeating four times...I simply couldn't believe it.

Cap I never considered...but you raise a good point to confirm. Seems my next step, though I had hoped to get more definitive proof of yes/no before doing so, is to replace radiator core and thermostat so as to rule them out completely. I simply can't make myself avoid that step before tearing down engine without rock solid evidence of blown HG's...which I don't have yet. A professional radiator flush (so there can be zero doubt there) may cost same as a new aftermarket radiator core...plus same effort to pull it and reinstall for the boil out flush. I wouldn't trust the in-car flush results at this stage given the ramifications...simply not definitive if it still overheats after the flush. Did I really completely rule out radiator blockage...100% doubt removed...did the in-car flush really do the job?

Here are other details I also must consider and ask you all to maybe also ponder as well...

The dealership (SAME one that diagnosed the blown HG's to prior owner) rebuilt the lower engine ONLY 15.000 miles ago...I have the prior owners receipt and the dealer service record. The engine was rebuilt for piston slap, so most everything in lower engine was replaced...all new pistons, verious gaskets and any/all wear items associated with such a repair...a very long list. So...heads WERE pulled, but there was no indication in records of a head job having been performed and I saw nothing about head bolt thread repairs being performed. Did Mr Goodwrench fix the threads or simply bolt the heads back on? Who knows! Only way to prove that one way or the other is to pull um. So this service history can be a negative to support blown gaskets...or a positive to suggest strongly toward an alternate cause for overheating. Honestly it seems very suspect that there is this overheating so soon after a major engine overhaul given the very rich history of head bolt problem. I deep down believe the dude flubbed the job...failed to fix the threads...but hey, who knows. If so, then it lasted long enough to clear their warranty period...but isn't that always the case with shoddy dealership repairs?

So...I'm still scratching my head gentlemen...what to do next.

Howard

hms200
01-10-11, 06:19 PM
yeah, that ^^^^ W/P belt/tensioner/pulley is suspect. On the driver's end of the front intake cam.

The constant bleed purge line runs from a hollow bolt/nipple at the rear of the thermostat housing and goes to a nipple on the top side of the coolant reservoir. That hollow bolt is one of the clog culprits - a proper sized drill and care is what it takes.......coolant should constantly flow into the top side of the reservoir - remove the line, hold it in the open filler neck, have an assistant start the engine, and it should show a steady stream.

Fans go to slow at 224 and fast at 236, and they run all the time in slow if any A/C mode is called for.

Open these and study them...............

++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++

Thx Submariner...

So if WP belt is turning nicely, with no noise and no indication whatsoever of wear then the idler pully is fine? I would expect idler pully to scream, rattle or make some sort of noise if it's bad...and also wouldn't it be doing nasty things to the WP belt?

Howard

hms200
01-10-11, 07:08 PM
yeah, that ^^^^ W/P belt/tensioner/pulley is suspect. On the driver's end of the front intake cam.

The constant bleed purge line runs from a hollow bolt/nipple at the rear of the thermostat housing and goes to a nipple on the top side of the coolant reservoir. That hollow bolt is one of the clog culprits - a proper sized drill and care is what it takes.......coolant should constantly flow into the top side of the reservoir - remove the line, hold it in the open filler neck, have an assistant start the engine, and it should show a steady stream.

Fans go to slow at 224 and fast at 236, and they run all the time in slow if any A/C mode is called for.

Open these and study them...............

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~

So...I "think" I know what one would expect from a suspect/failed idler and/or tensioner pully...but maybe not? Might there be issues other than what I noted in my prior supply if the pully has gone or is going bad that could be to such extreme as to cause overheating? I would think that what you guys are describing would be a condition to have either busted the belt, seized it altogether or significantly slowed it down whereby WP wouldn't be functioning properly, yes? Wouldn't I notice that in some way...squealing, smoking, burning...something? The belt is there, appears in fine condition and appears to be turning cleanly as it should...no unusual noise whatsoever.

So...on to 1) cap pressure validation, 2) thermostat replacement, 3) radiator core replacement...in that order? Any better ideas from anybody?

Thx

Howard

Ranger
01-10-11, 11:04 PM
I saw your post over at caddyinfo, but figured I'd respond here rather than duplicate it.

A leak down test is when you pull all the plugs and get each cylinder up to TDC compression stroke and pressurize it with shop air one at a time and let it set. If it has a leaky HG in that cylinder, pressure will drop and bubbles will eventually work their way to the surge tank.

The block test IS confusing. IF you did it shortly after adding coolant, it can give you a false negative. Is it possible that the fluid was old and unresponsive (not even sure if that is possible). I assume that you are only filling the surge tank half full and not to the top? That WILL cause it to overflow as the coolant heats and expands.

If the dealer did insert all 20 bolt holes as they should any time the heads are removed it would show it on the bill. That is insurance even if the threads are OK. They are in fact only aluminum and have been known to fail later after a removal and retorquing. Sometimes while retorquing and sometimes later down the road.

Before replacing any parts, the cap and thermostat can be checked and the radiator can be flushed, though I doubt the radiator is the problem unless as mentioned the previous owner dumped some stop leak in it.


I can make the engine overheat very quickly and easily with it simply sitting in my garage. With coolant level topped off I simply have to rev the engine up/down to ~2500 rpm's for maybe 5 minutes and then temp will start clocking past mid point.
5 minutes is probably long enough to reach normal operating temperature and with an uncapped system the coolant (50/50 mix) will boil at about 224 degrees so I'm not sure that is a good indication. If the system is capped and sealed, that's another story.

hms200
01-10-11, 11:43 PM
Thx Ranger...

I performed the block test properly and with good chemicals...it's a industry leading tester. Coolant wasn't just added, though it was new...added it and circulated thru the block before weather got cold since car is/was just sitting. Did the test with tank 1/2 full yes. though at one point it did boil up on me to where I sucked up coolant into the tester and contaminated that specific test.

Thx for info on leak down test. If I take things that far then I'll have to have a shop do it since I don't have the gear necessary for such a test.

I purchased the cap and stat tonight so I'll give them a shot. As much as I hate to, I'll most likely replace the radiator if cap/stat doesn't fix the issue before I take extreme step of diving into the engine. All things in perspective, replacing radiator is a low cost elimination since I can never be sure what prior owner may have done. At least then I will know for certain, and hey...I'll have a nice new radiator either way.

I'm trying now to find the shop bill for the rebuild to see what all I can spot. I reviewed in when I first purchased the car a few months ago, but I've since gotten a cram education so I should have much more insight on what to look for within the documentation.

So let me ask you...BBF didn't like my premature question. :)

Any idea if I can make the head bolt thread repairs with engine in car? I simply don't have facilities to pull or drop the engine is why I ask. Do you know how to tilt the engine forward? Norm said that's what I'd have to do for rear bank access, along with a 1/2" right angle drill, which I have.

Thx again...

HMS

postman2000
01-10-11, 11:52 PM
My car passed the block test. It is, in my opinion not that definitive of a test..My 2000 deville was acting weird for over a year before the headgaskets finally went completely..It would randomly overheat on some days..and then some days in the summer with 90 degree + days it would be fine.. I did it all, new radiator, new thermostat, new water pump, new surge tank..took off the purge line and hollow bolt..cleaned them thoroughly.. even when the gaskets were at their worst..when the car would overheat just idling..the car past the block test...thanks to Jake my car is running cool again..

98eldo32v
01-11-11, 12:09 AM
Thank you postman 2000.

These cars don't show definitive symptoms or clear cut symptoms showing "yes", it's the gaskets. As Postman stated his acted up over a year before it finally said enough.

I know to a lot of new comers to the northstar scene, you don't want to "think" the worst of your engine. Yet, it has been well documented that these headgaskets have no particular point when they fail. Some sooner, some later.

Of course, you check the simple things first, yet in the grande scheme of things, what's the worst thing that's going to happen? You have to do headgaskets? If you are aware of the worst case scenario and can live with that, then don't beat yourself up. Fix it and be happy.

The car I lucked up on went through the same thing. New radiator, water pump, thermostat etc. Just fewer things I have to replace, but in the end who knows. I may change all of that out to have peace of mind. Once I fix it, I don't plan on touching it again.

My studs are on the way......

Good luck with your repair, whichever route you go.

Ranger
01-11-11, 12:30 AM
So let me ask you...BBF didn't like my premature question.

Any idea if I can make the head bolt thread repairs with engine in car? I simply don't have facilities to pull or drop the engine is why I ask. Do you know how to tilt the engine forward? Norm said that's what I'd have to do for rear bank access, along with a 1/2" right angle drill, which I have.

Inserts, not studs CAN and have be done in the car. A few have done it, but general consensus seems to be it is MUCH harder. You WILL need a right angle drill. I think you'd tilt the engine by supporting the front of the cradle with a floor jack (after it's on jack stands), then pull the front cradle bolts and slowly lower the front of the cradle. That will tilt the front of the engine forward and give you some space at the firewall. Now I've never done this so I don't know how much you can lower it and what if anything has to be disconnected before you do it, like brake lines, A/C lines etc.

hms200
01-11-11, 01:14 AM
Thank you gentlemen...HMS

zonie77
01-11-11, 12:25 PM
With the extra info on the block rebuild it's surprising you would have HG problems but it could possibly be a problem from the rebuild. Possibly poor cleaning or a nick on the head surface ( Jake had a nick on a head that caused a problem.). We've heard of the original threads failing on reassembly so possibly a thread failure.

I would just do a simple flush on the radiator to see if stop leak or something was clogging it (you should see the crud coming out) but at the age of the car, and the lower costs of aftermarket radiators, a new one is not a bad idea.

The first bad HG (my brothers car) drove us crazy. He drove it with varying symptoms for about 6 months before we did the HG's. We did all the external fixes before a block test was positive (luckily the first, he had it done at a radiator shop).

I drop the cradle but people have done it in the car. It takes more perseverance and is harder but doable. You can make or buy a tilter (here's one http://www.etoolcart.com/engine-tilter-thx419x.aspx ). Tilting the cradle helps.

hms200
01-11-11, 01:19 PM
WOW...thx Zonie...I never knew there was such a tool for tilting the engine. So there is only one used rather than a set? I don't need to secure both sides? I'm safe to tilt the engine then without disconnecting this or that first once the stablizers are removed and the tilter installed in its place to pull engine forward from the top, right?

Well, for peace of mind (maybe wasted bucks, but hey) I last night purchased everything to prove beyond any doubt (hopefully?) to me once and for all that issue is in fact the HG's. I got cap, stat AND new radiator. I'll test everything part by part...cap-->stat-->rad. If it's by chance cap or stat then I may return the radiator...not sure yet. In any case I'm pretty darn sure at this point it'll prove out to be the heads, but as I've said before, I simply can't make myself tear it down without having first exhausted all other more simple possible causes since I can't get definitive proof otherwise. This isn't my first rodeo...I know vehicle mechanics pretty well (very far from helpless), but this ghost has really stumped me. Never before have I struggled so hard to validate yes/no on HG's. I'm NOT a parts changer by nature as a means to troubleshoot. I'm old school...need to determine root cause first via tests/data, but this bugger hasn't cooperated with that strategy thus far...so now I guess I'll do as far too many shops (the smart guys...LOL) actually do...start swapping parts until I find the cause...grrrrr. Cooling system isn't rocket science, nor should diagnosing blown HG's be...but this one so far is breaking that mold. Sounds like I'm not the first one as well to face this ghost from all I've read on web.

I've tried to give Mr Goodwrench benefit of the doubt on his rebuild by trying so hard to prove it's NOT the HG's. Because if he had done his job correctly and professionally then it should be VERY doubtful that there should be a head bolt failure after only 15K miles. GM published an extremely detailed service document for all their dealer shops on what's required when heads are removed for ANY reason. Only thing I could be understanding on for the dealership is if I find that Timeserts were properly installed but then have failed. At least then I would know he followed GM's directive, though flawed as it is with their poor solution of choice (Timeserts). If it does prove to be the heads then I strongly suspect the dude just slapped them back on and cranked um down. Why? Based on the shoddy reassembly I've detected so far with the engine...missing and loose nuts, bolts, clamps, etc. I found electrical tape holding together a split rubber L connector on crankcase vent tube going from front valve cover to throttle body for crying out loud. Huh? It took me an entire 5 minutes to replace with a proper new heat resistant rubber elbow...duh. Electrical tape?? Give me a break...simply no excuse for such lame lack of attention and professionalism on the part of a Caddy service department pro. The vehicle was serviced exclusive by that specific dealership all its life...so the finger prints I find belong to that establishment. So...one can only wonder what else...can have little/no faith that the dude followed proper procedure...but, maybe I'm wrong...we'll see.

HMS

RippyPartsDept
01-11-11, 02:05 PM
the timesert parts aren't cheap so they should be listed in your parts that they charged, but it is likely that they didn't timesert the block since it wasn't in for a head gasket/bolt failure... it would have been prudent to timesert the block just in case though but maybe the customer declined it or something... hard to tell that kind of stuff now though

hms200
01-11-11, 03:17 PM
Agree completely...still haven't found where I put that darn shop receipt though (still looking).

The rebuild was performed under a service plan, so you may be right about bypassing...I too suspect that. But, if GM has issued dealership advisement (they have) to timesert the heads when removed for any reason, then I don't see how service plan could have gone against that. But you're right...one will never know that kind of stuff...and I'll not know what was and wasn't actually done until/unless I pull the heads. One can sit around and guess/speculate all day long until the cows come home.

HMS

Ranger
01-11-11, 10:36 PM
Any chance you can stop in at the dealer on a slow afternoon (after the morning rush) and have them look up what they did (or didn't do)?

tateos
01-11-11, 10:43 PM
I suggest you be careful, especially if you install a new radiator, because the extra pressure in your cooling system caused by your blown HGs (yes, that IS your problem) could crack a side tank in your radiator - ask me how I know!

Also, if you do decide to tackle the HG repair yourself, I strongly suggest you remove the engine from the car to do it, and I strongly suggest you drop the cradle to do it.

I have never heard that GM said all head bolt holes must be timeserted when a head is removed...even though the consensus is that is the prudent thing to do. Actually, timeserts have a rep for a high percentage of failure - not sure if that is due to the product or the application; I used Norm's with good success - I think Jake's studs are a little better solution, so I would probably consider using Jake's if I had to do one in the future. Honestly, I don't see that in the cards - I don't expect to own another N* powered car; that's not a knock, but I've been driving Cadillacs with N*s since 1994, and when the '97 ETC and I part ways, I think it will be for some kind of hybrid/electric/super-duper gas saver vehicle - thinking about maybe a Volt, actually.

RippyPartsDept
01-11-11, 10:51 PM
:yeah:

we always do all 20 timeserts... (big serts actually)
there seems no point to get all that labor done just for a few headbolts leaving the chance of another failure and all that labor again to be done

Ranger
01-11-11, 11:28 PM
Thx Ranger...

Any idea if I can make the head bolt thread repairs with engine in car? I simply don't have facilities to pull or drop the engine is why I ask. Do you know how to tilt the engine forward? Norm said that's what I'd have to do for rear bank access, along with a 1/2" right angle drill, which I have.

Thx again...

HMS

See post #8
http://www.cadillacforums.com/forums/cadillac-seville-cadillac-eldorado-forum/219390-stumped-overheating-problem.html#post2464329

zonie77
01-12-11, 12:33 AM
WOW...thx Zonie...I never knew there was such a tool for tilting the engine. So there is only one used rather than a set? I don't need to secure both sides? I'm safe to tilt the engine then without disconnecting this or that first once the stablizers are removed and the tilter installed in its place to pull engine forward from the top, right?

One should do it but when you pull the heads you lose the place to bolt the tool. When you tilt it you have to be careful not to break things. Most engines can be moved quite a bit but you are the one responsible to stop in time.


Well, for peace of mind (maybe wasted bucks, but hey) I last night purchased everything to prove beyond any doubt (hopefully?) to me once and for all that issue is in fact the HG's. I got cap, stat AND new radiator. I'll test everything part by part...cap-->stat-->rad. If it's by chance cap or stat then I may return the radiator...not sure yet. In any case I'm pretty darn sure at this point it'll prove out to be the heads, but as I've said before, I simply can't make myself tear it down without having first exhausted all other more simple possible causes since I can't get definitive proof otherwise. This isn't my first rodeo...I know vehicle mechanics pretty well (very far from helpless), but this ghost has really stumped me. Never before have I struggled so hard to validate yes/no on HG's. I'm NOT a parts changer by nature as a means to troubleshoot. I'm old school...need to determine root cause first via tests/data, but this bugger hasn't cooperated with that strategy thus far...so now I guess I'll do as far too many shops (the smart guys...LOL) actually do...start swapping parts until I find the cause...grrrrr. Cooling system isn't rocket science, nor should diagnosing blown HG's be...but this one so far is breaking that mold. Sounds like I'm not the first one as well to face this ghost from all I've read on web.

You are not the first!


I've tried to give Mr Goodwrench benefit of the doubt on his rebuild by trying so hard to prove it's NOT the HG's. Because if he had done his job correctly and professionally then it should be VERY doubtful that there should be a head bolt failure after only 15K miles. GM published an extremely detailed service document for all their dealer shops on what's required when heads are removed for ANY reason. Only thing I could be understanding on for the dealership is if I find that Timeserts were properly installed but then have failed. At least then I would know he followed GM's directive, though flawed as it is with their poor solution of choice (Timeserts). If it does prove to be the heads then I strongly suspect the dude just slapped them back on and cranked um down. Why? Based on the shoddy reassembly I've detected so far with the engine...missing and loose nuts, bolts, clamps, etc. I found electrical tape holding together a split rubber L connector on crankcase vent tube going from front valve cover to throttle body for crying out loud. Huh? It took me an entire 5 minutes to replace with a proper new heat resistant rubber elbow...duh. Electrical tape?? Give me a break...simply no excuse for such lame lack of attention and professionalism on the part of a Caddy service department pro. The vehicle was serviced exclusive by that specific dealership all its life...so the finger prints I find belong to that establishment. So...one can only wonder what else...can have little/no faith that the dude followed proper procedure...but, maybe I'm wrong...we'll see.

HMS

Timeserts were the original repair, the studs designed for the N* came later. If buying a new kit I sould go with the bigsert, but if you are only planning to do one engine the studs are about the same price.

The poor workmanship might be an indication of HG failure from poor assembly. You'll have to take it apart to know for sure. Tightening head bolts by degree of rotation could let someone not paying attention under tighten a bolt. Lots of potential problems from someone not doing their job.

zonie77
01-12-11, 12:48 AM
I suggest you be careful, especially if you install a new radiator, because the extra pressure in your cooling system caused by your blown HGs (yes, that IS your problem) could crack a side tank in your radiator - ask me how I know!

Also, if you do decide to tackle the HG repair yourself, I strongly suggest you remove the engine from the car to do it, and I strongly suggest you drop the cradle to do it.



This is great advice. Most people who tried it in the car gave up. I'm not saying it cannot be done, just it is the hardest way to do it. Dropping the cradle is the easiest if you are only going to do one. They are made to be dropped and even though you can pull out the top it is harder until you learn the techniques.
With the cradle out you can access everything on the engine easily.

if you haven't seen this take a look:

http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/176057-n-engine-removal-newbee.html

ejguillot
01-12-11, 10:29 AM
+1 on the above. For a one time install, the time it takes to drop the cradle (and later install) is more than made up by taking less time (and aggravation) to do the repair work with the engine out of the car. And I have done the cradle drop and stud install at home, in the garage, and did 95% of the work myself (only time I had help was when a friend came over to help me drill and tap the holes in the block).

tateos
01-12-11, 08:54 PM
I'm one of those people who, as zonie writes, started out by trying to pull the engine out of the top and gave up. Once I resigned myself to dropping the cradle, as previously recommended by zonie, things actually became easier...a LOT easier. Also, when it came time to reinstall, a lot of the assembly that has to be done in the car, with great difficulty and access problems, was readily done; the cradle was out of the car and everything was right there in front of my big schnozz, with no obstructions - it was a real eye opener for me!

I too did 95% of the work myself, in my garage, with only a helper for the drilling/tapping, and also for the head bolt torquing.

Look here for zonie's thread:

http://www.cadillacforums.com/forums/cadillac-tech-tips/31831-n-head-gasket-repair.html

Here is my thread, with a few pics and several of my mistakes noted, including my initial desire to pull the engine out the top:

http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/126253-97-etc-n-head-gasket-project.html

bradmo
01-22-11, 12:42 PM
Check out this website for some pretty good indicators:

http://www.northstarperformance.com/main.php

hms200
01-22-11, 01:47 PM
Check out this website for some pretty good indicators:

http://www.northstarperformance.com/main.php

Thx Bradmo! Read the FAQ link "Is It Reall Your Head Gasket?". The article is dead on with no straight answers and many others points/areas I've struggled with is my attempts to diagnose to a definitive determination...remove all doubt. You should see a now MONSTER thread of mine on another caddy owners site in my attempts to reach that diagnosis...wow. Really great responses and really smart guys, but it's continued to be a very long and foggy road.

I will perform the highway road test EXACTLY as the article defines and see what happens.

I've asked this multiple times on both sites but let me ask again. :)

IF (I say if) issue is in fact my head bolts/gaskets then CAN I make the repairs with engine in car IF I go with Norm's inserts? I am a very able individual under the hood but I do NOT have facilities to allow me to pull OR drop the engine...absolutely cannot do either with what I have at my disposal (tools NOR garage). I've heard all the cons against such an "in car" attempt, but my question is still based on determining can I do it myself or MUST I farm the job out from lack of facilities for engine removal? To be clear...it's NOT lack of my mechanical abilities/experience here in my resistance to pull/drop the engine. I have no engine lift or stand, no car lift, no engine hoist, no ceiling clearance even if I had a car lift/hoist, etc. Each time I ask this I get back a host of caution on how much easier the job is once engine removed. But...as I said, my question is focused on can I do it myself or must I hire the job out...not how easy or difficult it will be. :)

I do have a 1/2 angle drill btw and I do understand why that would be needed...that's the easy part. I understand all about there being no proper clearance for in-car repair with the studs for back head (even if engine tilted forward to its max limit, avoiding damage to other things?), so I'm talking about Norm's inserts as my selection if done in-car. If answer is really, "Yes, but very difficult", then can anybody that's "been there - done that" provide some insight on specific areas of great struggle I would/will face for performing in-car repair?

Many thanks!

Howard (HMS)

RippyPartsDept
01-22-11, 01:51 PM
yeah the owner of that site is Jake aka 97EldoCoupe here and he is a supporting Vendor and advertiser here (you might see his banner ad at the top every so often)

he is highly respected here for saving many cadillacs with his patented stud kit
(and for other reasons, but i digress)

my advice would be to not repair in the car... very hard to do and higher chance of mistake that can't be fixed

hms200
01-22-11, 03:03 PM
Thx Rippy...your advice noted sir...thx much.

But, I'm also trying to understand specific difficulty areas I'd face if I must in fact make the repair and if attempted in-car. I do understand the precision or exactness required for drilling and the need to shelter everything from the aluminum shavings. What I'm wondering is access issues to be faced and dealt with on disassembly and reassembly (which I assume is where "very hard to do" comes into play?)...and any other associated access issues and how best (or IF) they can be overcome.

Norm's serts vs. Jake's studs...there is a very strong fan base on both sides for each solution...so I don't think that should really factor into a decision of yes/no on in-car, which I know you're not doing here...but others have with prior opinions/advice. Obviously Jake has a GREAT solution, but I believe so does Norm...each solution considered on its own merit and circumstances. I've even mapped out the drive from Lone Tree, CO to Jake's place if I simply trailered it to him...17 hrs 17 mins / 1148.43 miles. So, point here is that I'm looking at all options here IF the HG's are in fact blown, and that's not yet been proven beyond any reasonable doubt. Just looking ahead for if/when worst case is proven.

Thx

HMS

RippyPartsDept
01-22-11, 03:28 PM
you can't do jake's studs without pulling the engine... there is just not enough room the studs stick up too high to get the heads over them while the engine is in the car - at least on the firewall side

jake's solution is the best - and having him do the work for you is the best of the best... if you can afford it and can afford to wait (i understand he's got quite a few cars backed up waiting)

hms200
01-22-11, 03:55 PM
Thx Rippy...yes, I had pretty much understood that studs are completely out of the question if engine not pulled. From Jake's website I didn't get a sense of a long backlog. It actually said to pull her in on a trailer and then suggested go hang out at hotel for a few days while the job is done. Thx...appears I'll need to confirm on that if the repairs are required and if I lean toward that option of having him do the job. Lots of "ifs" at play here. :) But better to collect all facts and options in advance from my perspective...part of having eyes wide open.

Ranger
01-22-11, 05:15 PM
Yes, it can and has been done in the car. Not easy from what I hear though. Do a search for any posts by Mike Lawson. I believe he is in Ky and does them in the car.

RippyPartsDept
01-22-11, 07:58 PM
well i can't speak for Jake's current situation, but that's the feeling that i got from some of his recent posts... he's been moving his shop and still hasn't fully transitioned so he's doing more travelling that he should... plus he doesn't have a receptionist yet (still) - once he's back to 100% i'm sure you could get it done in just a couple days

00 Deville
01-22-11, 10:59 PM
Here's a couple of videos of Mike Lawson doing both the front and rear banks in the car.



http://www.youtube.com/watch?v=ISfcE69cikk


http://www.youtube.com/watch?v=6956YYLd8PU

hms200
01-23-11, 01:43 AM
Thx guys...and thx for the video links. Guess that's pretty good proof! :) Anybody have Mike's email address or know best way to reach him? I'd sure like to ask for any tips on disassembly, like tilting the engine forward for rear access to disconnect exhaust manifold and other hard to reach items back there. Also what does Mike do with heads once off to verify condition? Does he have the heads resurface, pressure tested and valves inspected? Also timing chains...tips for disassembly and reassembly...getting the timing right and tools needed.

Well...I failed the highway test as defined here...so I take this as my final validation I guess...unless there is radiator blockage, but I've seen nothing to make me really suspect that. I believe it's the HG's. Road test performed as defined in this link took temp up to and slightly beyond 145 degrees, though recovering quickly as driving intensity eased up. What blows my mind is how fast the temp recovers. I've never seen that before...very strange.

Here's the highway test conducted...

http://www.northstarperformance.com/hgfaq.php

HMS

hms200
01-23-11, 02:51 PM
My post lacked detail...so here is more info. I meant 245+...oops on that typo. All my prior highway road tests were fast and sustained, but were not really hard and aggressive. This time I buried my foot in the peddle, let off (not to 30 mph, but I slowed) and then buried it again...over and over. The inclines were best indicators...accelerated hard all the way up and that needle then would really start to move on me. I never took it far beyond 245 degree mark but I could SURE get it to that point and beyond easily enough, at will. I'm still surprised by how easily I can control the temp to either direction...that just seems so bazaar. When I ease off, the engine temp recovered immediately and completely. Never did I experience any bad engine performance as well (it always seemed happy), though never took it past slightly beyond 245.

Upon return to garage the car was back to normal temp, which as I said, it took little time for it to recover back to norm. Popping the hood, that engine simply was NOT red hot, not cooking...it was normal operation temp. Tank was warm to the touch...far from red hot...and same for the cap, though there was some minor residual smell of prior coolant steam when I popped the hood...minor, not extreme. There was no boiling activity/noise from within the tank...and no steam pouring from the cap or overflow tube. After cooling for a bit (maybe an hour) I released final pressure (small amount of remaining air pressure only, no major coolant discharge, other than maybe a few drips (new cap I had installed is the pressure release lever type). Sniffed the tank...yep, sure smelled of exhaust to me. I verified coolant level in tank (3-4 inches from top, not dry but seemed a bit low...did NOT add any coolant), reapplied the block tester to tank and it went from blue to green in short order once the bubbles started appearing...then to yellow...then water surged from tank and up into the tester as well...test over...popped the cap back on to stop the surge overflow onto my garage floor. I don't believe the coolant surge threw off test results. I believe it was a surge of exhaust gasses just before coolant surged from tank, like a burp if that makes any sense. Yes, once water hits the tester then all bets are off. When it turned yellow I quickly pulled tester from tank mouth to inspect and there was no water at the top yet...but it did come flowing up quickly from that point. Btw...after popping cap back on I went quickly to turn off engine...temp gauge sitting at high side of normal (~210 mark). I'll do the test again today with even less coolant in the tank this time because I didn't refill it after the surge event. Green isn't suppose to be an indicator of exhaust unless its diesel as I understand it. But it did turn yellow when bubbles started surging extra strong just before it overflowed. The tank smell was sweet and pungent, not that of just coolant.

So to me, all the outward signs and conclusion I'm sitting with at this stage appear to be a minor sustained head gasket leak under normal operation and major leakage under extreme load. That seems to be similar pattern described by others as well, which makes this such a tricky thing to diagnose, contrary to most vehicle blown gaskets where it's a true blow out rather than head bolt induced. Make sense? I may have forced a more extreme leakage with the intense road test, whereby I was then able to get more definitive outward signs this time. As for the plugs being perfectly clean in earlier inspection, not sure if it's possible, but maybe there is simply a one way leak happening...exhaust into coolant but no coolant into cylinders. Is that even possible you think? I'd say anything is possible from this point with the Northstar based on bazaar test results I've come up with to this point. Btw...I inspected pump belt again and still see out outward evidence of slippage...no abuse to the belt observed and not shiny. Also, no coolant leakage or smell anywhere else within engine compartment other than at the tank area.

HMS

RippyPartsDept
01-23-11, 03:51 PM
sounds pretty definitive to me

and N* will almost never mix coolant into the oil ... you will burn some off, but it isn't noticeable until later stages

hms200
01-23-11, 04:50 PM
Yep...very first thing I confirmed was no coolant in the oil. One mystery that still remains though is the near pristine condition of all 8 plugs that I observed when I performed compression test. If there is a coolant/exhaust exchange happening then I would have expected to see charcoal on plugs, or flaking matter or powder white deposits on plugs. I saw none of that...they looked completely normal...all of them...very clean/fresh. But, from everything I've read on this darn Northstar head bolt issue is that "old school" expectations of what to expect seem to be out the window. I even have a shiny new radiator core sitting off to the side, still boxed up, from when I could have sworn I was moving toward proving radiator blockage. I no longer feel that way though and can return the radiator if/when I feel safe/secure in doing so...or if I decide I don't want a shiny new radiator to go along the Norm's inserts repair job. :) I can't remove the engine, so Jake's Studs are ruled out if I do the repair myself. For me to do it, it'll have to be an in-car repair effort.

HMS

zonie77
01-23-11, 07:55 PM
hms, I just want to clarify something. Dropping the cradle only requires an engine hoist. If you have a way to lift the front of the body towards the garage ceiling you could do the work under it. The body without the cradle is surprisingly light.

hms200
01-23-11, 08:38 PM
hmmm...don't have a crane/hoist presently but that's not so expensive really from Harbor Freight. I may study/research that concept. Haven't really given it any study whatsoever so far since I had ruled it out from very beginning.

So, safely lift and support/secure front of vehicle how and how high? Engine hoist is to lower cradle down onto floor? I/m in a simple garage with plenty of work room but no ability to install a chain hoist to rafters or strong A-Frame. I'm just not well situated at present, huh? :)

HMS

zonie77
01-23-11, 09:30 PM
Take a look at the pics in this thread. You don't have to pick up the front end too far, but what's too far? 8' ceiling should be enough.

http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/5052-n-head-gasket-repair-part-i.html

hms200
01-23-11, 11:00 PM
Great info in the thread zonie, and the pics helped me to understand on lifting concept...thx much!

So...not much support out there for doing the heads in-car, though there is info and proof that it's doable. My case is lack of reasonable facilities for an engine removal + my engine lower block was dealer rebuilt only 15k miles ago, so I believe/hope that upper end is all that's needing attention. All the lower seals and such were done my dealer when they rebuilt for piston slap. Also had a GM certified tranny replacement by the same dealer on 20K miles ago, so no tranny or associated seals concern me there either. Very hard to accept (mind blowing) that head bolts would fail in 15K miles if dealer had performed a proper repair. CLEARLY they didn't refurbish the head bolts...proof of that soon to come I guess when heads are pulled. I actually have the service order from that repair and I see ZERO mention of inserts. I didn't even spot charges for new head bolts for crying out loud. ALL 8 pistons were replaced though so I can't see how job would have been done without pulling the heads. Maybe the head bolts were buried in the OEM head gasket set though, thus not listed as seperate items. The cost for 20 serts + labor should have been spotted though...not.

I don't know what condition to expect with my heads since they were pulled/replaced by the caddy dealer prior rebuild, but all indications is that they did NOT perform a valve job or any other reconditioning of the heads. It had 98k miles at that time and now has 114K miles...so I guess I wait to see how they look. Resurfacing is minimum I suppose, but it sure seems like one would want to have complete pro inspection and valve job performed if needed, right? But, I see no mention of such with any of the discussions?

HMS

Ranger
01-23-11, 11:57 PM
If there is a coolant/exhaust exchange happening then I would have expected to see charcoal on plugs, or flaking matter or powder white deposits on plugs.
Actually it's quite the contrary. A cylinder with a leaky HG will be the cleanest of them all. The plug will be cleaner than the rest. Something about the liquid vaporizing. I can recall pouring a glass of water down the carb of my '69 Road Runner while holding the throttle open to clean the cylinders. Probably didn't need it, but it sounded like a good idea at the time.

Heads, valves and guides almost NEVER need any work. Just insert it and replace the gaskets.


Maybe the head bolts were buried in the OEM head gasket set though, thus not listed as seperate items.
I think that may be the case because head bolts are not to be reused. I think a new set came with the gasket set.

drewsdeville
01-24-11, 12:32 AM
I don't know. Sometimes while trying to diagnose leaky headgaskets, I find the affected cylinder's spark plug is caked with some white crusty matter (deposits from cooked coolant?).

But as far as carbon goes, you'll never see any. And when you pull the head off, the affected cylinder will be squeaky clean from the thorough steam cleaning it's been getting.

hms200
01-24-11, 12:55 AM
So no resurfacing of heads required either? I need not suspect heads could be warped? Really...just slap them back on as is with nothing more than serts, clean block/head surfaces and new gasket set?

HMS

hms200
01-24-11, 01:02 AM
Very interesting on the squeaky clean...and as I had said, all the plugs were very clean as well...nothing. Well, my brain hurts from trying to figure all this out...must actually be a reverse engineered alian power plant...nothing fits any old school tried and true throubleshooting from all I've seen.

HMS

Ranger
01-24-11, 01:51 PM
So no resurfacing of heads required either? I need not suspect heads could be warped? Really...just slap them back on as is with nothing more than serts, clean block/head surfaces and new gasket set?

HMS

Correct on all three counts.

hms200
01-24-11, 02:49 PM
That's really great news for the ol wallet and for my peace of mind in getting this clearly confirmed. Thx for the confirmation Ranger and others!

I'm searching dscussion threads now for others that have tackled this in-car for specific gotcha's and disassembly tips. Not a ton of info found so far but I really do appreciate the warnings and advice already received as well.

So far I'm seeing following tips/warnings...

1. Strap on rear head to tranny is a bear for access.
2. To tilt engine forward I must remove front cradle bolts and disconnect front motor mounts and the dog bone brackets, yes? So tilt will NOT happen simply with a GM tilt tool that attaches where dog bone is now? I understand that bracket is mounted on front head...but my thought was to do rear head first start to finish, and then the front one...so I'd have the tilt bracket in place as needed for the rear bank. Today is first I read about removing front cradle bolts and disconnect front motor mounts - but I'm still early in my research.
3. HVAC Housing may require replacement - not sure I understand exactly what the "HVAC housing" is and I can't find that specific part listed anywhere. Is that the heater fan cover on firewall or what?
4. Timing effort greatly concerns me so far, but I've done minimal research so far in that area. Will I need to invest in a GM timing kit for this? I've read everything from "no brainer effort" to "very-very difficult to do in-car".
5. What else guys?

I don't want to over think this, but I do want to attack it properly prepared and do all in my power to avoid any/all costly or deadly (to the engine) mistakes along the way. I can't remove the engine in my specific circumstances, so I need to focus all my prep research based on the hard way (if that's so) of addressing it in-car. I fully acknowledge all tips and warnings against that technique, but I also see the comments of, "...but it has been and can be done." :) I'm betting that key is in the engine tilt magic for most access issues...so I sure want to understand that aspect very well.

HMS

Submariner409
01-24-11, 04:57 PM
With Cylinder #1 at TDC, firing stroke, here's the timing chain and sprocket mark setup.

There is a specific sequence to follow when setting and disconnecting the timing chains, chain tensioners, and removing/replacing the cam drive sprockets. It's pretty much straightforward, but you must do it correctly. It's not a no-brainer, but then again it isn't rocket science to a decent gearhead.

The oil pump, wrapped around the crankshaft snout, is driven by friction from the harmonic balancer torque - 37 ft/lb + 120 degrees. This is a LOT of torque. Lock the flywheel and do it correctly. Not enough torque and you wind up with no oil pressure.

If you don't have a GM/Helm Service Manual in front of you, either get one from www.helminc.com or ebay. Chilton and Haynes are useless for this level of work. Or, subscribe the car to www.alldatadiy.com.

zonie77
01-25-11, 01:20 AM
So...not much support out there for doing the heads in-car, though there is info and proof that it's doable. My case is lack of reasonable facilities for an engine removal + my engine lower block was dealer rebuilt only 15k miles ago, so I believe/hope that upper end is all that's needing attention. All the lower seals and such were done my dealer when they rebuilt for piston slap. Also had a GM certified tranny replacement by the same dealer on 20K miles ago, so no tranny or associated seals concern me there either. Very hard to accept (mind blowing) that head bolts would fail in 15K miles if dealer had performed a proper repair. CLEARLY they didn't refurbish the head bolts...proof of that soon to come I guess when heads are pulled. I actually have the service order from that repair and I see ZERO mention of inserts. I didn't even spot charges for new head bolts for crying out loud. ALL 8 pistons were replaced though so I can't see how job would have been done without pulling the heads. Maybe the head bolts were buried in the OEM head gasket set though, thus not listed as seperate items. The cost for 20 serts + labor should have been spotted though...not.

I don't know what condition to expect with my heads since they were pulled/replaced by the caddy dealer prior rebuild, but all indications is that they did NOT perform a valve job or any other reconditioning of the heads. It had 98k miles at that time and now has 114K miles...so I guess I wait to see how they look. Resurfacing is minimum I suppose, but it sure seems like one would want to have complete pro inspection and valve job performed if needed, right? But, I see no mention of such with any of the discussions?

HMS


The Caddy heads are well designed and warping,cracking, and burned valves are not common. If the engine is running well now it will run well after, just not overheating.

Even if you are not touching the bottom end, dropping the cradle makes the valve job much easier, and it makes the doing the timing very easy.The cradle serves as your engine stand, you just drop the cradle and do the heads, then lift the cradle back up.

The head gaskets came with the bolts from the dealer, I think Felpro sells them separate, but you may not see them on the receipt. If it wasn't an error by the mechanic it's possible the bolt threads were on the verge of going and failed shortly after the rebuild. Orrrrrrrrrrrrrrrrr... possibly it started to strip while being torqued and it was just ignored

hms200
01-25-11, 01:26 AM
Thank you submariner...info noted and saved.

HMS

hms200
01-25-11, 01:44 AM
Thx much zonie...info absorbed and noted.

That's very good news the heads are unlikely to require reconditioning. I verified with a GM OEM supplier that the OEM head gasket sets do include the head bolts. So your confirmation, what I have read elsewhere and their word answers that mystery. I just need to focus on "what" and "how" rather than "why". The "why" I could speculate all day long on and it would accomplish nothing.

So you are also for cradle drop as best option...appears to be the overwelming consensus here and the other site. Hmmm...

Any clue on weights...the cradle based engine assembly and also the car lift dead weight for front minus the engine?

HMS

Kefo
01-25-11, 07:11 PM
I have a question about JimD's temp gauge illustration, in my opinion my temp guage reaches the 1/2 way point rather quickly, after the first 10-15 minutes that the car has been running. Last Friday I took it on an 80 mile round trip drive in dreaded L.A. freeway traffic with the AC running, it was about 80 degrees outside I traveled in periods of gridlock traffic jams and at normal Highway speeds. During Highway speeds and daily driving conditions, my gauge is always right at half way or 210 degrees, in gridlock traffic the gauge sits in-between 210-225 degrees, and goes back to 210 when the traffic lets up, I have never seen it (in two weeks) go past 225 degrees.

Are these normal/acceptable operating tempatures for Northstar, is it normal that I reach the half way mark on the temp guage so quickly?

RippyPartsDept
01-25-11, 07:21 PM
Kefo - sounds normal to me.

zonie77
01-25-11, 09:17 PM
Thx much zonie...info absorbed and noted.

That's very good news the heads are unlikely to require reconditioning. I verified with a GM OEM supplier that the OEM head gasket sets do include the head bolts. So your confirmation, what I have read elsewhere and their word answers that mystery. I just need to focus on "what" and "how" rather than "why". The "why" I could speculate all day long on and it would accomplish nothing.

So you are also for cradle drop as best option...appears to be the overwelming consensus here and the other site. Hmmm...

Any clue on weights...the cradle based engine assembly and also the car lift dead weight for front minus the engine?

HMS

Unless you have even more extensions,swivels, and u-joints than I do I would recommend dropping the cradle. If you drop it flat and raise the body you only need some wooden blocks to raise it off the floor. The body feels very light, feels like less than an a V8 engine.

RippyPartsDept
01-25-11, 09:32 PM
plus you're not really lifting the whole body weight... just lifting the front while the back pivots on the ground ... leverage, physics and whatnot

97EldoCoupe
01-25-11, 11:13 PM
Goeteze was the OEM head gasket supplier for the Northstar, a division of Federal Mogul (which also makes Fel-Pro). Victor Reinz (a division of Dana) made many of the other gaskets and seals.

I talked to GM of Canada to get the HG's from GM without the bolts in the kit, but they would not do that- instead they just wanted to discount the gasket & bolt sets. Still, Chris @ Rippy would still beat GM of Canada's pricing by a long shot, even with my discounts.

Fel-Pro has been a bit sloppy with their quality control. I wish they'd be more careful with packaging.

hms200
01-26-11, 01:06 AM
Chris is the same Rippy that has made some replies here? Is ther a website or contact info for him? I have an online source for OEM parts, including the HG sets /w HBs...but I haven't shopped around enough yet to really get sense of how good their price is. In past they have had pretty darn good prices on true GM dealer only items and so-so on GM branded items that are also sold outside of dealers...like AC Delco as an example. I've always been very pleased with Fel-Pro, but I was advised within this or the other forum by several to definitely go OEM on these HGs...so I'm listening to that advice. Fel-Pro has gotten sloppy on all packaging?

HMS

hms200
01-26-11, 01:15 AM
Hey also...

Can anybody suggest best source for the factory shop manuals and any idea on what a great deal price might be for the full 3 volumn set?

HMS

00 Deville
01-26-11, 03:10 AM
Chris is the same Rippy that has made some replies here? Is ther a website or contact info for him?

Chris posts under the screen name RippyPartsDept he's the parts Guru at Rippy Cadillac here in Wilmington, NC. Make sure that you mention this forum to get the discount.

1-800-747-7922 or email him at parts@rippyautomotive.com

00 Deville
01-26-11, 03:12 AM
Can anybody suggest best source for the factory shop manuals and any idea on what a great deal price might be for the full 3 volumn set?


Ebay is normally the best deal on the Helms FSM.

RippyPartsDept
01-26-11, 09:30 AM
http://helminc.com to get the brand new FSM direct from Helm

Submariner409
01-26-11, 11:22 AM
Hey also...Can anybody suggest best source for the factory shop manuals and any idea on what a great deal price might be for the full 3 volumn set? HMS

See Chris's (RippyParts) post, and a new Helm set is, what, $135 - $150 ? eBay has used recent manuals all the time, but get a picture and firm price - usually $35 - $90 or so.

Take a look at www.alldatadiy.com. Then you get all the recalls, Technical Service Bulletins, Diagnostic Trouble Codes, and labor rate info, too.

hms200
01-26-11, 02:05 PM
Thx guys...

I just sent Chris an email for parts quote and I'll check tips on FSM sources. I did see a full 3 vol set on ebay yesterday for ~$120 I believe it was and a 2 vol set (minus wiring) in Amazon for ~$135 I think it was.

hms200
01-26-11, 02:11 PM
As for Alldata, I'm already subscribed for my 2000 Deville and have been looking it over for tips and diagrams on the Northstar. I believe identical engine for 2000 Deville and 2001 Eldorado, but there may be some differences between models for other connecting components, cradle, etc...yes?

HMS

Submariner409
01-26-11, 06:24 PM
Maybe some hoses, air ducting, intake airboxes, pipe routing, but the engine/transmission are basically the same.

hms200
01-26-11, 06:44 PM
Thx submariner...I went ahead and subscribed this vehicle thru 2016 earlier today. So no need remains to wonder what's different. :) My Deville is still covered thru 6/2014 also.

HMS

Ranger
01-30-11, 12:51 AM
Thx guys...

I just sent Chris an email for parts quote and I'll check tips on FSM sources. I did see a full 3 vol set on ebay yesterday for ~$120 I believe it was and a 2 vol set (minus wiring) in Amazon for ~$135 I think it was.

A brand new set from Helm Inc. is $135. Use that as a guide. Those Ebay prices are high.

hms200
01-30-11, 01:02 AM
A brand new set from Helm Inc. is $135. Use that as a guide. Those Ebay prices are high.

Yep...very high! I see a 3-vol set on eBay for $130 and I saw the new Helm price direct from them (and also via Amazon) for $135.

Just snagged a factory set (used) off eBay tonight for my 2000 Deville for only $20 + $9.95 shipping...so it is possible to get them cheap if patient. The 2000 Deville set will probably have much info I need, along with what's provided thru Alldata...but I'm keeping my eye out also for specific 2001 Eldo set.

HMS

zonie77
01-30-11, 01:29 AM
I got a 98 set for my 97 and the mechanical part is the same. There are probably electrical differences but for doing HG's you are fine.

hms200
01-30-11, 02:50 AM
Agree...I believe the mechanics are identical between the 2000 Deville and the 2001 Eldorado are very-very close. Engine removal between the two models would obviously be quite different, but mechanics of the engine itself I'd expect to be almost the same, if not exact. Example of engine differences...the 2000 Deville has water cooled alternator...2001 went back to fan cooled. Not sure what other subtle differences there may be...but I think they would be in fact, subtle.

I'll keep watching and snag an Eldo set if one happens along at the right price. 99 seemed to be a break year, at least for the Northstar...so 2000-2002 Eldo should be my targets I think. Agree? Maybe just 2000-2001 since I think there were some significant changes made with final model year, at least for the ETC...but mine is the ESC.

HMS

Ranger
01-30-11, 02:22 PM
As far as engines go, your Deville manual should do the trick. They have the same engines. Yes, there where changes and upgrades made in 2000. The rest of the Eldo got no changes once it was slated for extinction.

hms200
01-30-11, 03:01 PM
Yep...agree Ranger...thx. Major mechanical changes over the last 5-6 years I believe were traction control, extra HP, and new tranny. I think nothing mechanical changed in final 02 model year as well if I recall, other than a special collector option model offered with cosmetic option package.

If I stumble upon an Eldo set for the right price then I'll snag it for future repair value. Otherwise, the 00 Deville set + Alldata should have me covered for the HG project.

I picked up a nice (never used) 2-ton cherry picker (Sunex Model # 5218) on Friday off Craigslist for a great price, less than Harbor Freight best price and a much better unit I believe. A local water meter sales/repair/certification company had bought it for warehouse lifting of huge meters but it wouldn't work for them...so they dumped it cheap. A nice catch...and timely. :) So, one step closer to going the cradle drop route if need be...but to do so I'll still have to determine how/IF I can block up the raised front after lifting it with hoist so I can then remove hoist for pulling out the cradle from front. Only space I'll have for pulling out the cradle from under car is from the front (not enough space on sides). the unibody sides will support the front end lifted load (minus cradle) if weight properly distributed?

HMS

Ranger
01-30-11, 10:28 PM
the unibody sides will support the front end lifted load (minus cradle) if weight properly distributed?

I believe so.

zonie77
01-30-11, 10:41 PM
I had a bunch of 4x4"s from a construction project when we did the first one, I used pieces stacked up to support the body high enough to take the cradle out on jacks with the tires still on.

hms200
01-31-11, 03:03 AM
Thx zonie...that's exactly what I speculated would have to be done and was exactly my plan if jack stands will not work.

I just completed a trial lowering of the front cradle to test things out. Lowered front cradle about 2" and that provided about 1" extra access at firewall. I can lower a bit further I believe with no danger...nothing is in a bind thus far. I detached all hard lines that were bolted to cradle before the trial...lowered front of cradle down onto two jack stands...worked fine. Of course I completed a fair amount of the top end disassembly as well before the attempt...including the bones, cooling fans, radiator and more. I guess you can say my project is officially underway...just haven't committed yet to in-car or cradle drop. I have my hoist ready though if I opt for a drop.

HMS

hms200
01-31-11, 10:13 PM
Hi all...

Here's my latest update...

I snagged a set of Factory (OEM) Shop Manuals last night on eBay for a pretty good price - 2002 Eldorado, so I'll be well set with that info plus my Alldata access for my specific vehicle.

Project is now underway, finally. I have NOT yet committed fully on in-car vs. cradle drop...but I now have option to go either way since I now have a 2-ton cherry picker.

For the benefit of those that come after me on the blown HG's/HB's issue, I will provide below info. Maybe some will have less questions, concerns or worries on options as I've had up to this point.

Trial Effort to make Northstar Head Gasket / Head Bolt Repair with engine IN-CAR. It can be done...proof is out there. Question remaing is, CAN I DO IT? :)

WHY? I have no vehicle lift and only limited space. I do however now have a 2-ton hoist and a plan with insight on how to execute a cradle drop without a lift if in-car approach doesn't work for me.

1. Initial limited disassembly of top, including cooling fans, radiator, radiator tank, battery, air filter box, intake air plenum, both bones and other initial access items.
2. Did NOT remove or disconnect A/C Condenser or A/C system (not yet anyway)...condenser DOES seperate just fine from radiator if you figure out the trick (lift condenser up and back from radiator after removing a few bolts).
3. Jacked up vehicle from front cradle beam.
4. Placed jack stands under chassis on both sides, directly behind front wheels and BEHIND rear cradle (not ON cradle), jack stand height of 2nd notch from bottom setting (may vary depending on your stands).
5. Lowered vehicle onto the jack stands and tested stability.
6. Placed jack stands under front outer sides of cradle and raised to within ~1" of current cradle height, for safety.
7. Raised jack from front cradle to point of firm upper pressure on cradle, but NOT lifted off the jack stands behind front wheels.
8. Carefully inspected entire cradle area from underneath AND above and disconnected any hose straps and other attached items that would obstruct movement or be damaged by same. Only a few things were found that needed this (from underneath...most will flex or move on/with cradle.
9. Removed front cradle bolts (one on each side).
10. Lowered cradle onto the jack stands, thus lowering cradle about an inch.
11. Once again I carefully inspected intire cradle area, from below AND from the top...found NO obstructions or anything in a bind. Everything was either moving with cradle, flexing naturally (rubber hoses, wiring, etc) or was clear altogether.
12. Jacked up cradle off the front jack stands and then lowered the stands further. For mine that was to the bottom setting.
13. Lowered cradle back down onto the jack stands and carefully inspected entire cradle area yet a 3rd time.
14. Measured all clearances. Cradle in front has been lowered 5", clearance from firewall HVAC cover to back valve cover is now 3 1/2", front clearance still very good due to prior fans and radiator removal. Side access (both) are now more obstructed due to being lower. So, rear access is now very good and that is/was the primary area of concern for in-car effort.
15. Plan now is to swivel the cradle height up/down from this point, between 0"-5" lowered, as needed for project access.

Will keep everybody posted on forward progress from this point. Will now proceed to complete my top end disassembly, moving inward toward the heads, and see how that goes...so far so good.

I suspect that once top end disassembly is complete then there actually will be very little extra effort remaining for dropping entire cradle, if that may become necessary. But, if I can avoid that easily enough then I will have saved a lot of extra effort (maybe) though, so I'm approaching this with a "let's see" attitude, fully prepared to drop it if/when necessary...but will try first to prove in-car with minimal busted knuckles. Holding no false expectations here gents...if I must drop it, then so be it. I just wanna give the "old school" method a whirl first...call me stubborn...call me a rebel. :)) The cradle engineering is actually very slick I now see...no wonder you've all (most) have said, "drop it". If I had a car lift then I'd not be giving it even a second thought at this point.

HMS

wantboost
04-19-11, 05:40 PM
can u check cylinder temps with a temp gun?

hms200
04-19-11, 05:55 PM
can u check cylinder temps with a temp gun?

Fow what reason...to validate blown gaskets? Already confirmed it, have dropped engine cradle already and pulled both heads. Two failed head bolts on one bank and one failed on the other bank. Will be serting all 20 head bolts when I get back onto the project. Heads looked great...pistons also...just those pesky ol head bolts stripping out. Caddy dealer did NOT sert the block when they had recently rebuilt lower block...shame on them!

Do have a question guys...I cannot for the life of me get the spacers off on either side of block...the raised spacers on each side of head/block to hold it in place. Evidently the dealer tech must have used glued em in so something. Any suggestions gents? Do I dare try and drill/sert those threads with the inserts in place? Haven't measured yet to see if drill bit would even be long enough...doesn't sound safe to me though even if it is. ???

HMS

stoveguyy
04-19-11, 06:05 PM
spacers? you mean the hollow dowel pins to align the heads? if so, they are pressed in. easy to ruin them taking them out. you cannot drill thru them if you plan on serting the block. gotta come out.

hms200
04-19-11, 06:24 PM
Yep...that's what I was trying to describe...didn't know the correct name. So I'll need to manhandle them out for serting and then get new replacements? Do the new ones go right in with a hammer and wood block or how exactly? So they are called "dowel pins"...two per head...four total for engine? Any suggestions for removal? They are as tight as can be!!

HMS

RippyPartsDept
04-19-11, 06:30 PM
dealer probably didn't remove the heads when they did the reseal... that's another grand added onto the job at least (i would think)

hms200
04-19-11, 08:30 PM
Don't know...they "claimed" that, while they couldn't confirm it after the fact, the nature of job would have commanded head removal...and I tend to agree. They replaced all eight pistons, among others things, associated with head slap repair. Didn't you confirm for me rippy from parts list I sent you way back when that head gaskets was on that list?

So, anybody know sure fire way to remove the two stuck dowel pins (if that's what they are called) on each side and how new ones are best installed?

HMS

00 Deville
04-19-11, 10:07 PM
The head alignment pins are hollow... install a tight fitting bolt inside the pin. ... clamp vise grips on the pin... put a wrench on the bolt head... carefully turn the pin using both the vice grips and wrench until it can be removed.

Speedygman
04-19-11, 10:08 PM
Take a 5/8 x 11 Tap, cut threads inside hollow dowel about even with top of block, insert 5/8 threaded rod, use a stack of sockets around the rod, washer nut, tighten nut until it pulls hollow dowel out, or stick a bolt that will just fit inside hollow dowel, pinch dowel with vice grips and pull out.

Ranger
04-19-11, 10:16 PM
If that does not work, insert the threaded rod into the dowel and tack weld it to the dowel. Put a piece of pipe over it with the washer and nut and then turn the nut, thus pulling the dowel. No need to replace the dowel. Jake's stud kit comes with 4 studs that have a raised shank to replace the dowels.

RippyPartsDept
04-19-11, 11:24 PM
Don't know...they "claimed" that, while they couldn't confirm it after the fact, the nature of job would have commanded head removal...and I tend to agree. They replaced all eight pistons, among others things, associated with head slap repair. Didn't you confirm for me rippy from parts list I sent you way back when that head gaskets was on that list?

well yeah, now that you mention it i do remember... we've done a bunch of lower block seal repairs and don't take the heads off

i forgot it was you that had the piston repair also (and you sent me that parts list too) ...

so now you're saying that some of those bolts they replaced have pulled?
IIRC they had put inserts in your block, right? or did they just replace the headbolts? (which would be a big no-no any time you have a pre2005 N* head off)

wantboost
04-19-11, 11:33 PM
I'm askin if I can check with temp gun and how cause I'm gonna be buying a dts and wanna check it first

Ranger
04-19-11, 11:50 PM
No you can't.

hms200
04-20-11, 12:10 AM
Well...your guess is as good as mine on what they did or did not do. Nature of the prior repair dictated head removal, given that all pistons were replaced by dealer under prior owner.

They did NOT install serts...so no thread repairs done. Did they reuse the head bolts or replace? I suspect replaced since the new bolts are part of the OEM head gasket kits that were in the parts list. Evidently the dealer tech fool simply slapped on the heads with no regard for the well known thread failure issue. Even if none were failed at the time...I can't imagine him just slapping it back together without repairing the threads. Prior owner knew nothing about all this, so it's not like he opted away from thread repair costs.

Oh wait...it was a service policy repair. So...evidently policy company was calling the shots...shame-shame. Mr Goodwrench still should have notified prior owner to at least advise and give him the option if service policy wasn't gonna cover the extra work. If done at that time, extra cost wouldn't have been all that much.

So yes...3 of 20 head bolt threads were clearly failed when I removed them. I'll be repairing all 20 obviously...will be using Norm's Serts.

HMS

RippyPartsDept
04-20-11, 09:42 AM
reusing head bolts is VERBOTEN per the FSM

very very unlikely that they did that (especially since you paid for new bolts, like you said)

tateos
04-25-11, 07:41 PM
Take a 5/8 x 11 Tap, cut threads inside hollow dowel about even with top of block, insert 5/8 threaded rod, use a stack of sockets around the rod, washer nut, tighten nut until it pulls hollow dowel out, or stick a bolt that will just fit inside hollow dowel, pinch dowel with vice grips and pull out.

I did the "insert bolt, use vise grips" thing, but it marked up the outside of the dowel quite a bit. I ground down the marred exterior so the dowels could be re-used - could have bought new ones cheap enough, but couldn't be bothered with trying to track them down locally.

I really like your 5/8" tap and rod procedure - it leaves the exterior of the dowel in perfect condition!

RippyPartsDept
04-25-11, 11:38 PM
i didn't think that the dowels are really meant to be reused... we always put new ones in

tateos
04-28-11, 10:39 PM
i didn't think that the dowels are really meant to be reused... we always put new ones in

I agree, new dowels are the way to go, but if you have the old ones out and they're re-usable with little or no work, it's just easier to re-use than to go to the dealer and buy new ones - that's all I'm saying.

Mine were marred/knurled on the outside by the vice grip jaws - I just took off the high spots and they went right in. I actually installed them upside down, so the part that was sticking out of the block that was marred went inside the block upon re-install, and the part that was in the block and essentially perfect was left exposed for the head to fit over. It might have been a little rinky dink, I agree, but it's not really a critical area and all I can say is it worked for me.

RippyPartsDept
04-28-11, 11:56 PM
yeah i understand

hms200
06-17-12, 03:32 PM
Hello all -

Well, for anybody that may care or recall all my dialog regarding the head bolts issue with my 01 Eldorado...I FINALLY decided to finish my little project. Work and other life drama pulled me away from my project for over a year after having dropped the engine and pulled the heads - though I had already bought all parts necessary to repair.

Ok well, I finally jumped back on my project and almost completed. Jakes Inserts installed, engine reassembled (including timing), engine reinstalled in the car - finally. Took me a week of solid 8-10 hours days (took me longer than expected, but I took things slow and deliberate, plus cleaned and explored along the way). So now I'm at stage of all under the hood stuff remaining. Must reconnect wiring, vacuum lines, throttle body, grounds, radiator, A/C, etc - all the really hard work is done!!

I did amaze myself that I had pretty good recall on where I had left my project over a year earlier. Plus I had tagged everything pretty well and duct taped all bolts/nuts to their associated parts - so reassembly went very well - so far. Getting the engine back into the car - I could have used a shoe horn :) but went reasonably well - slow and deliberate, a few inches at a time, connecting things back up and fine tuning the alignment along the way. I did have alignment paint marks on the floor (made when I removed the engine) and other little helpful hints for myself - so reassembly/reinstall went remarkably well - only very minor coaxing required with final alignments.

Very close to final project end - wish me luck!! Maybe another week of part time effort remains once I get back to it. I also did a fair amount of preventive maintenance as well while I had easy access, including replacing alternator, crank sensors and throttle body boot. One thing I thought about doing but did NOT do was to replace the starter/solenoid - hope that decision doesn't come back to bite me in short order considering its location - yikes. It had no issues prior to tear down, but then same case with the alternator. So why didn't I replace it? Let a sleeping dog lay perhaps? I just kept thinking about getting a DOA Refurb or the refurb unit failing on me remature vs. the factory original that's on it now. Cross my fingers on that decision - have not seen any forum history of there being a weak starter to be concerned about.

In any case - amazing learning experience this project has been. I know much more today about the Northstar and all points in between from where I was when I began. A similar repeat project would be MUCH easier - first one is all a BIG lesson every step of the way. Noth too complicated though overall - but IS a very time consuming effort overall. WAS FUN!! I really enjoyed the challanges!!

Howard

hms200
06-17-12, 03:48 PM
BTW - a tip for those DARN dowels...

Nothing I could come up with would remove those pesky beasts!! So here is how I soved the problem and I worked perfectly...

1. Whacked off top of the pins with a cutter (leaving 1/2 inch or so.
2. Took dremel grinding bit in a drill and ground out one section of each dowel to weaken it (careful not to go all the way through)
3. Collapsed the dowel into itself, also using gentle coaxing with a chisel down the ground area and a screw driver down the sides once dowel was collapsed.
4. Pliers then and a little wiggling - dowels slipped right out easily and zero damage to block, block surface or the holes.
5. New dowels were installed as I reassembled engine after having installed Jakes Inserts.

Those babies were IMPOSSIBLE to remove for me without the above steps taken - this was MY remedy and I've seen many others offering tips, so not saying my solution was best way - was simply "my" way. :)

Howard

bill buttermore
06-17-12, 04:44 PM
BTW - a tip for those DARN dowels...

Nothing I could come up with would remove those pesky beasts!! So here is how I soved the problem and I worked perfectly...

1. Whacked off top of the pins with a cutter (leaving 1/2 inch or so.
2. Took dremel grinding bit in a drill and ground out one section of each dowel to weaken it (careful not to go all the way through)
3. Collapsed the dowel into itself, also using gentle coaxing with a chisel down the ground area and a screw driver down the sides once dowel was collapsed.
4. Pliers then and a little wiggling - dowels slipped right out easily and zero damage to block, block surface or the holes.
5. New dowels were installed as I reassembled engine after having installed Jakes Inserts.

Those babies were IMPOSSIBLE to remove for me without the above steps taken - this was MY remedy and I've seen many others offering tips, so not saying my solution was best way - was simply "my" way. :)

HowardHi Howard. Congrats on your progress so far. Steve (eyewonder) came up with what may be the easiest method yet to pull the dowels - I used his method and it worked pretty slick. Find a tap that cuts into the dowel and cut some threads. Insert a bolt. Pull the bolt with a slide hammer or similar. Steve's job is documented in "Saga of a naive hg repair."

Ranger
06-17-12, 09:53 PM
The other way is to insert a length of threaded rod into the dowel and then tack weld it to the dowel. Drop a pipe over it. Put a washer over the threaded rod and then a nut. Tighten the nut and thus pull the dowel.

hms200
06-18-12, 12:20 AM
Hi Howard. Congrats on your progress so far. Steve (eyewonder) came up with what may be the easiest method yet to pull the dowels - I used his method and it worked pretty slick. Find a tap that cuts into the dowel and cut some threads. Insert a bolt. Pull the bolt with a slide hammer or similar. Steve's job is documented in "Saga of a naive hg repair."

Thank you sir.

Yep many creative ways to get it done. I didn't have a welder nor a tapper with bolts. Just devised a way using what I had to work with. Those bad boys are a bear that folks should be warned about so as to prepare them with a list of ways/ideas on how to overcome without damage.

Jakes kit worked wonderful btw. Instructions could have been more clear on exact placement of the serts within the holes but norm quickly confirmed that I was reading placement correctly. .
Howard

97EldoCoupe
06-25-12, 04:22 PM
Jake's Inserts? I am missing something....

hms200
06-25-12, 05:04 PM
LATEST UPDATE...
Ok, so with engine reinstalled into my vehicle I was then able to transport it to my new home in Dallas (I've relocated from Denver to Dallas).

Almost finished with the project. All "under the hood" reassembly has now been completed, except the following. I'm very-very close now to closure on this project.

Remaining:
1. Radiator, fans, upper/lower hoses, and tank
2. Condensor and recharge A/C (with a new accumulator)
3. Oil & Filter
4. Battery
5. Air Filter Assembly
6. Alignment

Btw...I now also know exactly how it takes to dig down to the hidden starter if/when it fails - 45 minutes! Not so bad really. Ha Ha...um...I found a long, unattached battery lead just hanging there by battery tray as I started removing all my tied back wiring, hoses and such. Gulp...I FORGOT to attach it to the Solenoid before installing the intake manifold...grrr. So lesson learned...install intake manifold AFTER engine is back in the car - LOL

So...anybody care to wager if my baby will crank on first attempt after such a major surgery? :)

hms200
07-01-12, 04:32 PM
Gents...project is complete...ALMOST.

Appears I forgot to plug in engine temp sensor as I installed engine. I'm getting no response from temp gauge though all other elec is fine.

Any tips on where sensor is located and if I will have access now that engine installed and everything else is connected?

Also check engine light is on. Can I clear codes to reset the light?

Engine runs great btw.

Howard

hms200
07-01-12, 04:47 PM
Jake's Inserts? I am missing something....

LOL...just spotted my error...sorry about that. Norms Inserts used...no clue how I shifted to jake on the updates...did not go with the studs.

Howard

Submariner409
07-01-12, 08:40 PM
Any tips on where sensor is located and if I will have access now that engine installed and everything else is connected? Also check engine light is on. Can I clear codes to reset the light?

ECT sensor is on the right rear (bellhousing) end of the engine right at the head/cylinder block seam - just about in front of your gas pedal toes. Hope you have long fingers.

Clear codes - and have them stay gone ??? It depends on what is setting the SES light.

hms200
07-02-12, 07:30 PM
Hmm...I will inspect that side and location of engine again, but I didn't spot it or any dangling unspoken for connector wiring. I do recall plugging a simple 2-wire connector in that area though during final under the hood assembly - suspect that was it. I do now also seem to recall the sensor...but I'll double check.

However...I DID find a dangling connector with a rather short extension on opposite side of engine rear corner (passenger side toward firewall), but cannot for life of me understand what I failed to connect back there. I've checked everything I see near there...access is so darn tight back there that it's extremely difficult to see well. I checked all the few obvious connections that the short length could reach. I cannot see rear head area though below the water bypass lines. Any ideas on that and can it can be associated with temp gauge not functioning you think? I do need to find where that connector goes...either a 3 or 4 wire flat connector.

Blown fuse perhaps? The temp sensor and gauge were both working perfectly before I dropped the engine - was reporting the overheating state just nicely.

hms200
07-03-12, 06:42 PM
ECT sensor is on the right rear (bellhousing) end of the engine right at the head/cylinder block seam - just about in front of your gas pedal toes. Hope you have long fingers.

Clear codes - and have them stay gone ??? It depends on what is setting the SES light.

Ok - I found the sensor and disconnected harness connector. Not by visual, but rather by feeling around from under side - only access I had. Reconnected and now temp gauge works fine. On the other side, against firewall, I also found where that connector belonged...a senor on rear head corner. If I remember right it's a sensor that appears to scan exhaust timing sprocket, but not sure of it's true function. Anybody know?

Ho boy - so now I have a massive leak in the A/C suction/discharge hose. Not sure exactly where, but I tested by shooting a can of refrigerent into the system after I was unable to pull down a vacuum - yep, massive leak. Maybe rubber hose got pinched somewhere along the process of cradle drop or reinstall. In any case, just ordered new line from Rock Auto.

The Check Engine light is still on...assuming I need to clear all the trouble codes stored from prior engine issues, and also most likely from the recent sensors not responding due to my lapse in connectivity during cradle reinstall. Isn't there an onboard controls trick for reading the codes and clearing? There is such for my Deville.

Howard

bill buttermore
07-03-12, 07:11 PM
...On the other side, against firewall, I also found where that connector belonged...a senor on rear head corner. If I remember right it's a sensor that appears to scan exhaust timing sprocket, but not sure of it's true function. Anybody know?...

If your engine is like mine, I'm thinking that would be the cam position sensor.

Submariner409
07-03-12, 08:03 PM
Read and study the OBD-2 procedure in the sticky post ^^^ "How to pull codes". It's all built into your car.

The CaMshaft Position sensor uses a Hall effect trigger to calculate piston TDC for timing reference. If it fails or has no signal the ignition system defaults to the limp home timing settings.

vincentm
07-03-12, 09:24 PM
CMP isnt hard to replace either, one 10mm bolt and shes out, but dont do like i did. Wait for the engine to cool :banghead: it also helps to have skinny hands

raymondk
07-04-12, 02:23 PM
This is for future reference since I didn't see the history here. I never did see a definitive diagnosis or whether the gasket was actually leaking or if any head bolts were loose or had failed threads.
The rapid heat-up and subsequent boil-over indicate the lack of any coolant flow. Does the lower hose get hot when this is occurring? Does the radiator get hot? Start it cold with the fans running full speed in manual. The air should get hot from the radiator and it should a long time to get hot. Watch the engine temperature to see if the temperature rise is gradual or is there a sudden jump. Take out the thermostat and establish full flow by starting it cold, then slide off the upper hose at the radiator. It should be a deluge with a throttle blip. I know it sounds stupid but it sounds like the water pump has no impeller or is somehow blocked. A head gasket builds up pressure in the cooling system from the leakage of combustion gas which displaces the water with subsequent overheating from a lack of water. Yours sounds like it is overheating while full of water. Either the pump isn't pumping or the radiator is not allowing flow. What does the heater do? With full flow it should get hot quickly with the engine. We are assuming that you have a properly installed 16 pound coolant tank cap. Anything less will let the water out.

hms200
07-04-12, 11:04 PM
Hi Raymond. This very long thread provides all the history. Issue was definitely the dreaded failed head bolt threads. I repaired by the book using Norms Inserts. Was a really big job start to finish given that it was my first northstar head gaskets repair effort. After doing this one I learned a ton so if ever a repeat it would be half the effort.

Howard

hms200
07-22-12, 05:44 PM
Ok well...new problem gents...

A/C is final remaining issue. Was determined that the main AC hose had a major leak, so I replaced the hose and the drier/accumulator. So...then pumped down system and attempted to charge. Compressor never engage and message center displayed "Low Refrig AC Off" and low side gauge is near pegged out. Was not able to get more than little over 14 oz of refrig into system, but with no positive results. System almost seems plugged up. Compressor is connected, and all line sensors as well, unless there is a hidden sensor that I'm not seeing.

Anybody care to suggest what this issue might be? Compressor seized? I can't really say if AC was working before I toke into the engine. It was winter and I had just bought the car, so I can't be certain of AC prior to that. I "thought" it worked...but maybe that was just an assumption. Sure seems like a failed compressor to me. AC compressor fuse is good but I don't know how to test the relay or if that should be considered suspect or not. Any ideas?

Ranger
07-22-12, 09:58 PM
You have to clear that low refrigerant DTC to enable the compressor. Do it with everything hooked up and ready for charging or it will disable again. It gets disabled when it's low on refrigerant to prevent damage to it.

hms200
07-23-12, 01:42 PM
Thanks Ranger - yes I read other threads after posting my question and saw that. Worked like a champ...the battery disco trick did it for the immediate, and then I also went in and cleared the codes as well. That also turned off the check engine light - so all is good. A/C charged up perfectly - ice cold. This project is now officially complete once I get the alignment and fresh inspection/registration. She runs like a top - not even tracking bad (perfect actually) given that alignment not yet performed. All the help and advice provided by you really smart folks all along the way has been greatly appreciated!! Made the major undertaking so much easier and definitive. It's always great when there is validation, given that repair manuals are always lacking some little tip or tid bit along the way. Nothing replaces good ol hands on prior experience. The giving nature and level of expertise of this forum is simply amazing.

So...my near mint condition 2001 Eldorado now has new life and will be screaming down the road again after a quick trip to DMV this week.

hms200
08-26-12, 02:21 PM
Gentlemen - I'm sure glad this is a hobby project for me!! LOL

Ok, so I got past the A/C issue - she is ice cold!!

BUT....

Q1 - She STILL overheats!! No clue if original owner ever used any snake oil (stop leak or other mystery/magic substance) by chance in an attempt to stop the overheating issue - I've sent that question to him and still awaiting reply. I'm trying to troubleshoot what may now be causing the overheating. Radiator might be stopped up or restricted if any substance was used to try and fix the issue before?

Q2 - She still has the Check Engine Light condition, even after resetting all the codes multiple times. I'm getting a code P0300, random misfiring. Symptom is low idle, idle a little unsteady, a little bit of slight lurching/jerking when put in gear at idle. She will even throw a new 0300 code by simply sitting at idle for maybe 5-10 minutes. All the performance symtoms disappear though if not at idle. There is a long list of possible causes, so hoping maybe you folks can help me here...hopefully not the symptom of failed head gaskets.

•Already installed new crank sensors before installing engine - so that suspect is ruled out (I hope)
•Just replaced spark plugs (though others looked near new) - so that's ruled out
•Just replaced cam position sensor, with no change - so that's ruled out
•No vacuum leaks that I can detect
•Fuel pump (weak pressure) isn't suspect I think because she runs fine at higher speed
•O2 sensors are commonly misdiagnosed as culprit - but seldom are the root cause, as I understand it?

So I'm stumped...aside from leaking head gaskets (I SURE hope not!!), it could still be a number of other things not yet replaced or checked...
•Spark Plug Coil Pack (either/both)
•O2 Sensor (either/both)
•Defective EGR
•Defective Throttle Position Sensor

I can't hardly imagine the check engine or overheating are still directly associated with head gasket issue/repairs. Repairs were done carefully and exactly to spec, plus reassembly and torque of head bolts also done exactly to spec. This is a true head scratcher.

Any insight you gents may have with any of this will be greatly appreciated.

Howard

vincentm
08-26-12, 05:09 PM
Just do the damn block test people, it clearly should be the first thing done...

Submariner409
08-26-12, 05:39 PM
Quite a turnaround from Post #119.

Yes, do the cylinder block exhaust leak test (regardless of what you did with Norm's Inserts) and use the car's built in diagnostic system to get any stored trouble codes: Every one of your imagined or "felt" problems will set some sort of malfunction code.

All the parts and sensors you replaced or mentioned, if faulty, would have sent bells ringing and codes a-setting.

hms200
08-26-12, 06:14 PM
Yes...well, post #119 was before I saw that the P0300 code would return. Also before I took her for an extended spin before going to get inspection prior to DMV visit (obviously nixed the inspect/DMV trip), and before I noted it would still overheat. I've in fact been using the onboard diagnostics system - clearing all codes, only to have the P0300 continually reappear regardless of all efforts thus far. No other codes are being thrown.

I performed the block test (many times) way back when I was trying to confirm head bolt issue - but never got a clear positive..in spite of fact that I later proved it was head bolts/gasket after tearing it down. So, I didn't hold strong stock in that test with the Northstar. Ok, I can certainly pull my tester out again and give it a whirl.

Just pulled off EGR to inspect and clean...wasn't excessively dirty or stuck. No change - still throwing same code after sitting at idle for ~5 min. Front coil pack inspected again also - no evidence of arcing or other external visible damage. Rear coil pack obviously tougher access, so have not done another inspection yet for that one.

CadillacLuke24
08-29-12, 09:39 PM
Gee whiz, overheating after Normserting it. YUCK. Leaks anywhere? Purge line clogged?

hms200
08-29-12, 10:15 PM
Nope...no coolant leaks and purge line flows perfectly.

HMS

CadillacLuke24
08-30-12, 01:19 AM
Don't kill me, please :duck: but...

Did you use the right mix?

Did you insert all the holes properly? I can't think of much that would make it overheat.

hms200
08-30-12, 02:33 AM
Yep...wish it was a simple answer. Mix is typical 50/50 and when you say "holes" I assume you mean the block inserts. Everything done by the book and very carefully. So I am seriously stumped as well because clearly I've missed something. I will certainly perform the block test as several suggested. I still have the misfire code that is being caused by something. Hoping it's a componant causing the misfire and that maybe the misfire is root cause for the overheating. I can't hardly imagine the head gaskets are still leaking. I'm not a gearhead rookie, though this was my first northstar head gaskets/bolts repair. Many other similar mechanic repairs (including heads/gaskets across multiple models) done in past...just not northstar, and there is a big difference in the overall project. If really bored (ha ha) go read this entire thread to understand great detail I applied and all the really great help and advice I received here all along the way. I will figure this out. On the "holes" I even called norm on the phone during repair to carefully clarify on proper insert depth since his instructions could be read two ways...so I didn't want to assume. He's a really great person...he actually cares and didn't treat as a dumb question. Spent time with me walking me through depth measurements to make sure I was good before applying the locktite.

HMS

CadillacLuke24
08-30-12, 04:18 AM
:D I was bored earlier, and I did read the thread. Yup, that's how I :cool: roll.

:histeric:

Joking aside, this is weird. You said earlier you couldn't seem to find the "ghost" about this problem, and it seems the damn thing is still present. I certainly do not doubt your repair skills, as you mentioned you've done stuff like this before. I guess I think at my level, and many times I do some pretty dumb stuff. I can't immediately recall the details of your pre-gasket repairs, but I'd check the thermostat next. That would be my guess. If, and when, you lost coolant, what did you refill with? Check the water pump. The water pump pulley may not be out of the woods either. Perhaps your radiator is clogged? That seems like a stretch, but who knows.

Go through the cooling system methodically and carefully. Good luck, and have patience. You can never have enough of that working on these cars.

hms200
08-30-12, 03:09 PM
I replaced the thermostat back before, when doing initial troubleshooting. Also the water pump (belt/pully/impeller/idler) is fine. At this point I'll perform the block test since I'm not prepared to start swapping out expensive parts in attempt to shotgun the standing misfire trouble code. It could be one/both coil packs, EGR, o2, TPS...any number of things. But as previous poster pointed out, other codes most likely would be thrown with any of those items in addition to the P0300. I've already eliminated the less costly possibilities. Misfire can even be associated with leaking heads I do believe. So...

But...This misfire trouble code was even present back before I tore engine down. I had assumed it was directly related to the overheating from blown gaskets. Fact that it still remains present today after reassembly is why I try to think it's a failed componant...though there was zero doubt that the HG's were blown and block threads (two on one side & 1 on the other side) had given way before. I'm trying hard to believe that car had two problems...head bolts/HG and the misfire issue, both being unrelated...at least that's what I TRY/WANT to prove. That is really making a long stretch though I tend to think as well. I do obviously have to diagnose to eliminate possibility that the heads are still leaking (block test).

Submariner409
08-30-12, 03:27 PM
2001 - coil cassettes with individual ICM's - have we been there yet ? One coil breaks down when hot ? A carbon tracked (old) coil/plug boot ? How about individual fuel injector operation ? Cracked/tracked spark plug insulator (guaranteed intermittent miss) ?

hms200
08-30-12, 06:21 PM
The coil packs (either side or both) have indeed been considered as a high probablity target for the very reason you stated...due to potential excessive heat failure from the prior HG overheating condition. I stated that is a recent post above, but hesitant to shotgun replace due to high cost. The boots I've inspected multiple times (during engine tear down and reassembly and during very recent plugs replacement). None of the boots appear damaged, brittle or otherwise compromised. Brand new OEM plugs - replaced them the other day in order to rule them out. Individual fuel injectors - all connectors were double checked and reseated, but have not taken a screwdriver or wood to try and listen to each one for firing.

Honestly, I hold next to no confidence in the block test...but I do still intend to perform the test, perhaps this weekend. I have a tester /w fresh chemical and I do know how to use it. However, I was never able to get a definitive positive test result when troubleshooting via same test originally when it was 100% confirmed after tear down that the HGs were in fact blown.

Ok - so am I correct that misfiring can potentially cause measurable overheating - what I'm experiencing? It's not mega misfire...most noticable when engine at idle and in gear (rolling at idle speed as example - slight jerking). The single P0300 code will be thrown in about 5-10 minutes, even if it just sits at idle in garage. I can clear the code (resulting in light going off) and it will be right back in another 5-10 minutes. At sustained higher speeds its far less likely to appear...until it's had chances to idle (like at a light).

RippyPartsDept
08-30-12, 06:43 PM
what color is the fluid that you're using for the block test?

the best fluid is very dark, kind of purple ... if you have a lighter color fluid that could be the problem with you block tests

jimsbox
08-30-12, 07:05 PM
If I am not mistaken the coil packs are interchangable. Are you only getting a generic 300 c0de or any more specific codes (301 to 308). If you do swapping the coil cassettes should produce a different 30x code if the pack is defective.

hms200
08-30-12, 07:23 PM
It's dark blue in color and it is fresh. Haven't seen the purple color before...hmm.

hms200
08-30-12, 07:28 PM
The coil packs are not interchangable from right/left sides, if that's what you mean. I do believe they are interchangable across a number of years/models, if that's what you mean. Well I don't know if there is a specific code to be thrown if a coil pack is misbehaving or not, other than for any residual engine problems that can result, such as the misfire P0300. Nothing more than that one code - consistantly the only code that gets thrown.

jimsbox
08-30-12, 07:34 PM
I was mistaken about being interchangable front to rear. 0301 tob 0308 codes identify which cylinder is misfiring, 300 just means a misfire

hms200
08-30-12, 07:43 PM
I don't get a 0301 or 0308...just 0300. You mean one code would indicate left bank and the other would indicate right bank? I'm not aware of any way with my built in to get other data, such as anything down to a specific cylinder number?

CadillacLuke24
08-30-12, 08:35 PM
One code can indicate which CYLINDER is misfiring, i.e. 0301, 0302, 0303.....

Coil packs and plugs have been mentioned. You've replaced the plugs recently, yes? If so, I'd take it to a big chain auto parts store and see if you can get a definitive answer on the misfire, so you can replace the packs. IMHO, though, I'd replace both and be done with it :D

Ranger
08-30-12, 10:11 PM
Your onboard diagnostics will only give you a P0300 code. AutoZone's scanner will point to the offending cylinder P0301, P0302 .P0303, P0304 etc.

I am pretty sure your ignition cassettes are interchangeable. I think the only difference is the color.

Have your codes pulled by AZ and then swap cassettes and have then read again. If the misfire follows the cassette, you've found your problem.

RippyPartsDept
08-31-12, 09:46 AM
the cassettes are not interchangeable due to their shape but the ICM inside them is interchangeable between cassettes ... although usually the ICM is fine and the problem lies in the coils

and getting the specific P030x code is about the only time that you would need to get a scan done at autozone, o'riely, etc

Submariner409
08-31-12, 11:51 AM
I have two brand new DELPHI coil/ICM cassettes for a 2002 Northstar engine sitting on the bench as I type. They are identical except for color. The ICM's are the same GM P/N.

If you check the orientation of each cassette you'll see that they're identical. I'll upload pictures of the two side-by-side if necessary. Otherwise look at the thumbnails in RockAuto and or the diagrams in GMPartsGiant.

FWIW, I picked these two up in '09 when RockAuto blew them out at $108 apiece.

RippyPartsDept
08-31-12, 02:04 PM
Sub - they are different GM part numbers

1104076 - left/front/grey
1104075 - right/rear/black

the only difference could be the color but that wouldn't make sense... there's got to be some internal difference

Ranger
08-31-12, 03:49 PM
I could be wrong Chris, but I swear that the only difference is the color. That's probably the reason for the different part numbers.


Sub,
You must have a parts store in your garage.

hms200
08-31-12, 05:11 PM
Ok well - this is all very interesting dialog, because I do really want to replace the coil packs - cost having been only reason I've resisted so far.

Rock Auto current price is $178 (right/black) and $188 (Left/Gray) + shipping - typical 5% discount. This is for the DELPHI (OEM) /w module.

AutoZone only carries their house brand (Duralast), plus only the Gray (L) one - and they do not specific for Left or Right (just color Gray) - $193

O'Reilly Auto only carries the Left/Gray only in DELPHI (and they do specific 1 per vehicle, so they are saying Right side only I assume) - $329. They also have L/R in BWD...$194 (R-Gray) and $212 (L-Gray)

Expensive buggers!!

hms200
08-31-12, 05:15 PM
Ok well - this is all very interesting dialog, because I do really want to replace the coil packs - cost having been only reason I've resisted so far.

Rock Auto current price is $178 (right/black) and $188 (Left/Gray) + shipping - typical 5% discount. This is for the DELPHI (OEM) /w module.

AutoZone only carries their house brand (Duralast), plus only the Gray (L) one - and they do not specific for Left or Right (just color Gray) - $193

O'Reilly Auto only carries the Left/Gray only in DELPHI (and they do specific 1 per vehicle, so they are saying Right side only I assume) - $329. They also have L/R in BWD...$194 (R-Gray) and $212 (L-Gray)

Expensive buggers!!

Correction on the O'Reilly BWD colors...intended to say it's Left/Gray & Right/Black...the standard GM color scheme.

If I do bite the bullet and replace then I do believe I'll go with Rock Auto Delphi.

Submariner409
08-31-12, 05:15 PM
Sub - they are different GM part numbers

1104076 - left/front/grey
1104075 - right/rear/black

the only difference could be the color but that wouldn't make sense... there's got to be some internal difference

There is a 2001 SLS two blocks from here that is running two black cassettes right now, and over the years there have been pictures of 2000+ Northstar engines with a black cassette on the left (2-4-6-8) bank.

hms200
08-31-12, 05:19 PM
Hmm...and as I said in last post, AutoZone only sells one part (the gray one)...assuming qty 2 required per vehicle I guess.

Oh wait...just checked AZ site again and the note says "Front/Gray".

Submariner409
08-31-12, 05:41 PM
Hmm...and as I said in last post, AutoZone only sells one part (the gray one)...assuming qty 2 required per vehicle I guess.

Oh wait...just checked AZ site again and the note says "Front/Gray".

Any junkyards in the area ?? Northstar coil cassettes are a dime a dozen at a DIY pick-a-part.

hms200
08-31-12, 05:42 PM
Ok - all seriousness aside - I discovered what the true difference is...

The color coding between the two is special GM instructional design. It's purpose is to help us all better understand which direction the engine goes back in after dropping it to make the mandatory H/G block repairs. :bonkers:

RippyPartsDept
08-31-12, 05:45 PM
yeah i guess the color difference would explain the part number difference
just doesn't make sense as to why the color difference then


oh well

hms200
08-31-12, 05:46 PM
Any junkyards in the area ?? Northstar coil cassettes are a dime a dozen at a DIY pick-a-part.

Nice idea! I may take that route - drawback is chance of getting a bad one, but if price is right then I may risk having to do a warranty swap (which I'm sure they would give me a short warranty...maybe).

jimsbox
08-31-12, 09:06 PM
Because the rear valve cover is black and the front one is aluminum colored so it makes as much sense for the packs to color coordinate

Ranger
08-31-12, 10:03 PM
Generally speaking, the ignition cassettes are pretty reliable. Probably more so than an AutoZone Don'tLast part. I would not hesitate to use a junkyard cassette. I would NOT use an AZ cassette.

hms200
09-12-12, 06:41 PM
Replaced both coil packs and boots with new Rock Auto OEM units - no change. :(

RippyPartsDept
09-12-12, 07:57 PM
What plugs are you running?

hms200
09-12-12, 09:03 PM
Standard OEM plugs. I just recently replaced them as well in attempt to eliminate as suspect. The old ones were also OEM.

AC Delco 41-987

Howard

Manic Mechanic
09-13-12, 12:29 AM
Gentlemen - I'm sure glad this is a hobby project for me!! LOL

Ok, so I got past the A/C issue - she is ice cold!!

BUT....

Q1 - She STILL overheats!! No clue if original owner ever used any snake oil (stop leak or other mystery/magic substance) by chance in an attempt to stop the overheating issue - I've sent that question to him and still awaiting reply. I'm trying to troubleshoot what may now be causing the overheating. Radiator might be stopped up or restricted if any substance was used to try and fix the issue before?

Q2 - She still has the Check Engine Light condition, even after resetting all the codes multiple times. I'm getting a code P0300, random misfiring. Symptom is low idle, idle a little unsteady, a little bit of slight lurching/jerking when put in gear at idle. She will even throw a new 0300 code by simply sitting at idle for maybe 5-10 minutes. All the performance symtoms disappear though if not at idle. There is a long list of possible causes, so hoping maybe you folks can help me here...hopefully not the symptom of failed head gaskets.

•Already installed new crank sensors before installing engine - so that suspect is ruled out (I hope)
•Just replaced spark plugs (though others looked near new) - so that's ruled out
•Just replaced cam position sensor, with no change - so that's ruled out
•No vacuum leaks that I can detect
•Fuel pump (weak pressure) isn't suspect I think because she runs fine at higher speed
•O2 sensors are commonly misdiagnosed as culprit - but seldom are the root cause, as I understand it?

So I'm stumped...aside from leaking head gaskets (I SURE hope not!!), it could still be a number of other things not yet replaced or checked...
•Spark Plug Coil Pack (either/both)
•O2 Sensor (either/both)
•Defective EGR
•Defective Throttle Position Sensor

I can't hardly imagine the check engine or overheating are still directly associated with head gasket issue/repairs. Repairs were done carefully and exactly to spec, plus reassembly and torque of head bolts also done exactly to spec. This is a true head scratcher.

Any insight you gents may have with any of this will be greatly appreciated.

Howard

Hello Howard I just noticed your post was so long and had some recent activity so started at the back and read to here. I think I know where you're at right now. Here's some advice.

On question 1, it still overheats. I would suspect the radiator for reasons you stated. But how and or when does it overheat? It would seem from your posts that it overheats gradually on long trips, is that the case? Does it cool back down if you slow or stop? Basically I understand it overheats but it would help to know under what conditions and how severe.

Question 2, Code P0300 : Random misfire. Sets at idle. Idle is notably low and rough. Runs fine under load and at higher engine speeds (With full power on tap right? A clogged cat will cause misfires and overheating but would also severely limit power).

Ok here's some clarification, a misfire that ONLY occurs at idle or very light throttle loads is almost never ever related to the secondary ignition. The secondary ignition is the business or working end of the ignition i.e. plugs, boots, coils. When those components fail the misfire will always get worse under higher compression loads (under more throttle). At idle the engine is burning the amount of air trapped by the cylinders in a vacuum, very little air and fuel. Air is what an ignition must fight or overcome to produce a good spark at the plug gap, it is actually a very good electrical insulator. So at idle it has very little work to do as it's actually easier for the spark to jump the gap under vacuum than it would be with the plug exposed to the open air at it's barometric pressure. On a running engine when you open the throttle and pack 200 PSI into that plug gap the ignition is put to the test, the spark voltage will follow the path of less resistance. If there are carbon tracks leading it to ground it would rather go there than jump across the plug gap filled with high pressure air. Same goes for a hole in a wire or boot, the voltage will find it easier to travel down the ceramic insulator and out of the hole in a boot or jump out of a wire at a point where the insulation is weak than jump that little gap full of air. So all of this being said, you're getting a misfire at idle that is apparently scattered about two or more cylinders but goes away when you make the ignition work harder. Stop spending money and time on the secondary ignition, that's not where you'll find a solution to this.

Sensors that are bad enough to cause a misfire almost always set a code for the problem before the code for a misfire, esp. if you're driving it around without a miss under load. So for now don't start swapping out O2 sensors, cam and the like.

What an engine does have at idle is a very small amount of air needing a even smaller puff of fuel. The ratio of air to fuel is very important because at idle there's so little to light off that if it's not correct it probably won't even burn (this is a misfire). You said you have already checked for vacuum leaks and found none, and I don't doubt this due to the fact that the idle is low. If you had leaks the idle would be too high if anything, esp. in open loop (cold start). If anything you may not be getting enough air to idle properly and cause a random miss. I would like you to check your throttle body and make sure the throat and blade are clean and there's no excesive coking in the area where they meet. If so clean it out. This engine is still a cable throttle so you have an Idle Air Control valve on the side of the throttle body, this is the plug that's on the top of the throttle, not on the side which the position sensor (reading from the shaft). Remove the Idle Air Control solenoid valve itself and clean it with throttle cleaner spray and a old tooth-brush or similar. Clean both and see if the idle comes up and clears.

Since the amount of air trapped in a cylinder at idle is very small (vacuum) the mechanical compression building ability of the cylinder it's in must be very good. A cylinder that bleeds down even 30% of it's compression will miss at idle because too much of the small charge leaks away before it can be lit, but under throttle the 200 may be 140 or even higher because the engine is running faster and there's less leak time, but the point is a weak cylinder will start firing when you feed it enough air. That doesn't mean that the air/fuel ratio will be spot on, but that it will com-bust and not be a miss. If the throttle assembly is supplying enough air but the miss is still evident and low rough idle then pull all the plugs, block the throttle open, and measure the compression on all cylinders. They should all be over 175 and relatively even. If not that's where the problem is and you will have to go further to find out why. It could be pressure sealing problems or pressure building problems (valve timing).

If compression is good and you're getting enough air to idle that narrows it down to fuel and spark timing.

Lets start with fuel. Random miss, low rough idle. No air/fuel codes. No injector circuit codes. Runs good under load. This leaves partially clogged injectors as an most likely fuel delivery issue possibility. Since the car sat up, likely with fuel standing on the injectors for a while, when you put your project on the back-burner and took care of more important things it's very possible that the fuel varnished or evaporated leaving petroleum residue in the injectors. When this happens they have a hard time making those small little puffs of fuel needed to provide the proper amount of fuel at idle. What ends up happening is that they may not spray at all unless they are open a longer time like under load. Or they do flow but it just bleeds through around the muck. It make collect a few pulses of fuel that drip off in a bunch causing a few lean misses followed by a rich miss and then repeat. If this is suspected you could have a good shop do an injector flush on the engine. One that plumbs into the fuel rail and runs the engine on a flammable detergent designed to remove these residues and carbon deposits etc. It takes about a hour and usually cost about $150-200. The chemical kit itself has more than doubled in price in the last ten years. It will usually renew a set of old clogged up injectors.

Now the spark timing. This engine's spark timing is completely controlled by the programming in the PCM. This programming references all the engine's sensors and determines when to fire the spark. There's nothing you yourself can do to change, adjust, or effect timing other than drive it. But The PCM needs good information to generate proper timing. If the PCM is getting some bad information or is referencing it incorrectly you can have incorrect timing. Usually timing type sensors work better at lower speeds because they have more time to switch, if they are starting to malfunction it starts to show up at higher speeds where they loose precision. So I don't think you have a bad sensor. What I wonder is if the PCM is referencing the crankshaft sensors correctly because you have replaced both of them and had the timing components at least off (I don't know what you did or did not replace in this area). When you do those things you change the input signal's profile. Sometimes it's enough to confuse the PCM. When initialized on the new running engine the PCM stores a sample of the crankshaft sensors signals and uses this as a reference to ever changing input signals to determine exactly what the crank is doing. Knowing what the crank is doing tells the PCM things like where it currently is, whether it is slowing, speeding up, or steady. Then it knows when to send the next spark and other cool stuff like if that cylinder just misfired. Even compression changes like new pistons and rings will change the rate of crankshaft travel after each firing event and skew the calculations if it's basing them on a now incorrect or outdated reference. Even old sensors change the signals up enough to cause ghost misfires that aren't actually misfires in the physical world. In order to account for these changes the PCM has a function called a "Crankshaft Variation Relearn" which is a scan tool initiated PCM process that has strict conditions, not hard but must be followed to the letter and the engine must at least start and run long enough to reach 160* before it can begin. The process will have one rev the engine up to a level high enough in park/nuetral for a long crank coast down without fuel. During this time the PCM re-samples all the crankshaft signals and stores the new profile to start referencing running condition signals against. So I could be that you have made enough changes in this area at one time to make the current reference sample cause problems with spark timing at idle. The same as before, a good shop and or technician should be able to perform this function for you for a reasonable fee. I have over $10,000 of my own money invested in my scan tool and my boss has supplied two other brands for us to use also that have similar costs. The amount of time it takes a tech to do this, about 15 minutes, is not the only consideration in how much you should pay. Also with a good shop/tech you pay for knowledge and experience. We see stuff overlooked or unknown to DIY'ers all the time. We charge up front for this, not tell you later that you need to pay me before I tell you something I noticed yesterday, that would be dumb. But that all being said this should still be at $50 to $120 charge. Get one done in any case, I've seen that alone clear up a rough idle on brand new vehicles that the dealer has told the customer "Was within specs" and that there was nothing that could be done about it. Yeah well most of the best techs don't work at dealers. Some do but it seems like a bunch of dummies love it there.

Go through this methodically and see if it gets your misfire squared away. I think the two problems are separate but as stated I would need some more information on the overheating to advise any further there.

Vernon

hms200
09-13-12, 01:42 AM
Wow!! Great detailed info Vernon...thx much!

As for radiator, prior owner did reply to my question and said he never used any snake oil. I do still have new radiator all boxed up though that I bought way back before when I wasn't yet convienced of the head bolts problem...never installed it. So...maybe I just go ahead and swap it out? It will overheat slightly with just idle on a hot day. On highway it will can get to two o'clock, but never into the red. Driving around parking lot easy to test for normal performance (not driven hard) it goes to slightly beyond TDC...
Maybe 10 minutes past 12 o'clock.

On misfire issue...you touched on one point that was to be my next suspect...crank sensor relearn process. I actually printed out both methods...shop procedure using diagnostic tester AND the highway DIY procedure. I replaced both crank sensors while engine was out and I had simple access as just a PM replacement...but then I forgot all about the relearn step.

Your suggestion on injectors and the sensor both make total sense as suspects. I did clean the throttle body completely during reassembly so that is ruled out...it's very clean. I also cleaned both the sensors, but maybe not well enough? I also replaced the intake plenium during reassembly as it was torn. So the top sensor might be a suspect target...and the injectors. Also tested intake manifold the other day for leaks by spraying brake cleaner (as good as starter fluid?) along intake manifold base with engine running to test for leaks. No results...engine idle didn't respond...so no gasket leaks there I think.

Howard