: Hot Hot Hot Is Gone - Finally



MUGSANDLUKE
10-03-06, 02:09 PM
:excited: RERFERS TO THREAD "HOT HOT HOT" ON 09 06 06 - THE HEAD GASKETS HAVE BEEN REPLACED AND IT SEEMS TO HAVE SOLVED THE PROBLEM, FINALLY. FORTUNATELY I HAD EXTENDED INSURANCE COVERAGE SINCE THIS JOB WOULD HAVE COST A SMALL FORTUNE. THE GASKETS SHOULD HAVE BEEN REPLACED FIRST AND ALL THE CRAP COULD HAVE BEEN AVOIDED. WHY DOESN'T CADDY COVER THIS PROBLEM? IT IS OBVIOUSLY A DESIGN FLAW AND THERE ARE THOUSANDS, MAYBE TENS OF THOUSANDS, OF NORTHSTARS OUT THERE WITH THE SAME PROBLEM. WELL NOW I HAVE A NEW WATER PUMP, NEW RADIATOR, NEW THERMOSTAT AND HOUSING, NEW BELT AND ALL SORTS OF OTHER NEW STUFF THAT PROBABLY WASN'T NEEDED AT ALL. IF ANYONE ELSE HAS A SIMILAR PROBLEM, REFER TO ORIGINAL THREAD, AND HAVE THE HEAD GASKETS REPLACED TO SAVE YOURSELF A GREAT DEAL OF TIME AND AGRIVATION.:thumbsup:

eldorado1
10-03-06, 03:17 PM
I Think Your Capslock Is Stuck On, But Okay... And Congratulations On Getting It Cool Again

hey... Why did it uncapitalize my sentence, but not yours?

MUGSANDLUKE
10-03-06, 05:38 PM
My fault on the caps lock. OOPS! Sorry. I went through three months of grief trying to get the overheating under control. This is a lousy situation since Caddy knows about and acknowledges the problem, hence the design of Timeserts, but they won't pony up to the bar and replace the headgaskets on their defective N*'s. They are playing the odds that by the time the head gaskets go bad, the vehicle will be out of waranty and been sold as used maybe 2 or three times. They are winning this one by not paying for their own mistakes. Not nice! That's big business. If some people with a few bucks decided to move ahead with a classs action suit, Caddy would be backed into a corner that they would have to buy their way out of. :stirpot:

So be it. I've vented enough. Hope you never have this problem.

AlBundy
10-03-06, 09:34 PM
Sorry about your gaskets. I like many here pray it does'nt happen to us that's why we try to maintain our vehicle superbly. I always try to tell any Caddy owners who don't know about this site to check it out and try to tell them about the coolant and the sealent tabs so this kind of thread can be avoided but if it happens to me I'm sure you will still read a similar thread posted by me.

MUGSANDLUKE
10-04-06, 10:46 AM
I hope it doesn'e happen to anyone else as well. I bought this Deville DHS used with only 47000 miles on it. It was completely serviced when I bought it including brakes, rotors, belts, oil, filter, cabin air filter, all other conceivbable items including the anti freeze. Unfortunately the Caddy poltergeist had already invaded the N* and it wasn't very long before the overheating problem began. Just a warning to all N* owners for engines built from 1998 - 2002 - Change the anti freeze and flush out the cooling system every year or every 25000 miles without fail! It's all you can do to help prevent the gasket gremlin from attacking, and even then there is no guarantee this won't happen to you too. Caddy should definitely step up and take care of their manufacturing defect for all of those suffering with it. How can they admit there is a problem and then not take care of it? These are not cheap cars. When they run, they run great, and this is probably one of the best riding and handling luxury cars I have ever owned. Just kill the gremlin before it gets you!

blb
10-08-06, 11:13 AM
You won't see the problem disappear until GM installs Timeserts from the factory. You won't see that happen because GM still has the "short term, penny wise/dollar foolish, mindset" that they can save a few cents per car by not doing it when the engine is built. Meanwhile, GM's market share continues to decline, and more and more people will never go back to GM after experiences with Northstar headgasket issues, V-6 intake gasket problems, the list goes on and on. The junkyards around here are full of Northstar equipped Cadillacs that look like new, but are junked because the cost to fix them is more than the vehicle is worth. If you can turn a wrench, aren't afraid of hard work, and have some time on your hands, you can pick these cars up cheap, put some time into them, and you will have a decent vehicle when you are done. Otherwise, stay away from them. The used car lots are full of these vehicles that have been traded in because the owners have seen the typical early warning signs of impending headgasket failures, and have unloaded them in time.

dkozloski
10-08-06, 11:22 AM
You won't see the problem disappear until GM installs Timeserts from the factory. You won't see that happen because GM still has the "short term, penny wise/dollar foolish, mindset" that they can save a few cents per car by not doing it when the engine is built. Meanwhile, GM's market share continues to decline, and more and more people will never go back to GM after experiences with Northstar headgasket issues, V-6 intake gasket problems, the list goes on and on. The junkyards around here are full of Northstar equipped Cadillacs that look like new, but are junked because the cost to fix them is more than the vehicle is worth. If you can turn a wrench, aren't afraid of hard work, and have some time on your hands, you can pick these cars up cheap, put some time into them, and you will have a decent vehicle when you are done. Otherwise, stay away from them. The used car lots are full of these vehicles that have been traded in because the owners have seen the typical early warning signs of impending headgasket failures, and have unloaded them in time.
Which V6 are you talking about? 3.2L, 2.8L, or 3.6L? This is a new one on me and I'm familiar with a whole herd of these things.

blb
10-09-06, 08:48 AM
DKOZ, You're kidding right? Do a Google search for the full story , but here's part of it:

The intake manifold gasket issues are a huge problem on the 3.4 V-6s. In the minivan applications, they are very expensive to fix because they are very difficult to work on because of space constraints. Complete failure of the gasket will allow oil and coolant to mix, and could cause complete engine failure. Fortunately, the gaskets tend to fail slowly, so most of the time, the problem can usually be caught and repaired before catastrophic engine failure.

On the 3.8 V-6s, the plastic intake manifolds (no gaskets are used on these) warp after repeated thermal cycling allowing coolant into the intake causing, at first, intermittant misfires, and in more extreme cases hydrolocking the engine.

Ranger
10-09-06, 11:47 AM
DKOZ, You're kidding right? Do a Google search for the full story , but here's part of it:

The intake manifold gasket issues are a huge problem on the 3.4 V-6s. In the minivan applications, they are very expensive to fix because they are very difficult to work on because of space constraints. Complete failure of the gasket will allow oil and coolant to mix, and could cause complete engine failure. Fortunately, the gaskets tend to fail slowly, so most of the time, the problem can usually be caught and repaired before catastrophic engine failure.

On the 3.8 V-6s, the plastic intake manifolds (no gaskets are used on these) warp after repeated thermal cycling allowing coolant into the intake causing, at first, intermittant misfires, and in more extreme cases hydrolocking the engine.
That's not true. The problem is the EGR "Stove Pipe" that comes up through the manifold just behind the TB. Hot exhaust gasses eventually cause it to get brittle and deteriorate it. Coolant flows through that portion of the manifold and the TB. That is where coolant intrusion comes from. I R & R'd one on my wifes '96 Bonnevile a couple of years ago and I machined a necked down "Stove Pipe" so as to have an air space between the pipe and the manifold to prevent it from happening again.

MUGSANDLUKE
10-09-06, 12:15 PM
In view of tghe original discussion regarding the head gasket problems on N*'s, Cadillac is hell bent on destroying their own image by not addressing the design problems they know exist in large numbers. As was stated above, the American car makers are being beaten up by the Japanese manufacturers because the Japanese guys back evgerything up with a great product and a great service with a very high level of customer support. Quite a few friends of mine have switched tio Japanese products, although built oin the U.S., and have nothing but praise for service, product quality, product longevity, and finally lasting value. We, the U.S. manufacturers are their own worst enemy as is evident by the head gasket problems that Caddy won't back up for their customer base. Another slap in the face to the guys in Detroit. They are circling the drain and have to address their quality and service issues before they get flushed all the way down. The Caddy is a great car, when it runs, and a bear to fix when it doesn't. Especially with little or no financial support for design defects. I'm sure their are many of us out their that feel the same way.

blb
10-09-06, 01:05 PM
MUGSANDLUKE, You're absolutely correct. The headgaskets have been a weak point in the Northstar ever since the 1993 introduction. Seven years later in 2000, they changed the headbolt thread, but this has done little to solve the problem. Now we have the same known issues with 2002 and 2003 models ten years later, and still, the factory is not installing Timeserts when the engines are built. It's a shame because otherwise, GM would have a great product. It's hard to have sympathy with GM's economic woes when you see these types of issues not only throughout various GM engine families, but to let this continue on their flagship brand for more than a decade is inexcusable. Granted, without exception, every Domestic and Foreign brand has some skeletons in the closet and I'm sure we could all name more than a few....but its how the companies deal with them that make or break customer loyalty.

eldorado1
10-09-06, 01:20 PM
MUGSANDLUKE, You're absolutely correct. The headgaskets have been a weak point in the Northstar ever since the 1993 introduction. Seven years later in 2000, they changed the headbolt thread, but this has done little to solve the problem. Now we have the same known issues with 2002 and 2003 models ten years later, and still, the factory is not installing Timeserts when the engines are built.

I think they changed the thread engagement length, not the thread itself. In 2004 they went to a m11-2 thread, which I think might just solve the problem. It would likely pull out the threads if you had to replace the head for any reason, but it would not pull out in the first place.... which I think is the point.

blb
10-09-06, 02:45 PM
I think they changed the thread engagement length, not the thread itself.

I understand the thread was changed in Model Year 2000 from a fine to a coarser thread because the height of the thread was higher (ie: larger dimension from the root diameter to the outer most diameter of the thread) on the coarse thread which would allow for more engagement into the tapped holes in the block. Hopefully, the change in 2004 when they went to a M11-2 thread will solve the problem. I guess we will know soon.

chevelle
10-09-06, 03:37 PM
The overall head bolt length changed in 2000 model year simply due to the design of the new cylinder heads. Basic thread engagement remained the same...just the overall bolt length was longer in 2000 because the head bolt bosses are higher in the new heads. The thread pitch did NOT change in 2000...only the length.

Minor changes to maximize thread engagement were made thru 2000 and 2001 model years.

The thread pitch was changed in 2004 to a coarser pitch thread for improved thread engagement. Bolt length remained the same as was changed to in 2000. The coarser pitch thread was concurent with the longitudinal Northstar engines in the rear wheel drive cars.

All of this is very simple to the naked eye if you just look at the parts....like someone who is working on them all the time might do.....

blb......for someone who supposedly knows all about these things and "works on them all the time" and has supposedly seen "all these failures" you sure don't know much about the details or what headbolts go where......hmmm...

zonie77
10-09-06, 03:37 PM
It would likely pull out the threads if you had to replace the head for any reason, but it would not pull out in the first place.... which I think is the point.

In my experience the threads were pulled out before the wrench touched the bolt. There was little or no tension on some of the bolts and those had the threads pulled. Those were also the bolts at the leakage spots.

eldorado1
10-09-06, 05:26 PM
In my experience the threads were pulled out before the wrench touched the bolt. There was little or no tension on some of the bolts and those had the threads pulled. Those were also the bolts at the leakage spots.

exactly - on the 93-2003's....

I think you'll find the 2004+ models will no longer have that happen..... however...... you'll probably still have to timesert it if you need to remove the heads for whatever reason. Maybe not though. I'd probably do it just for peace of mind. Nothing like putting an engine back together and having your last head bolt just spin.

MUGSANDLUKE
10-09-06, 07:38 PM
The shop owner desrcibed the Timesert as some sort of an attachment to the thread end of the bolts before they are inserted into the holes and they actually took the place of a helicoil. I didn't get to see one before the engine was re-assemled. What do they actually look like and how do they work if anyone knows? Just curious. the N* is running great since the HG's were replaced. An amazing amount of power and no overheating so far under any condition. I have my fingers crossed and I find that I am constantly looking down at the temp guage to see if there is any movement. I guess I'm still gun shy.

AlBundy
10-09-06, 07:58 PM
The shop owner desrcibed the Timesert as some sort of an attachment to the thread end of the bolts before they are inserted into the holes and they actually took the place of a helicoil. I didn't get to see one before the engine was re-assemled. What do they actually look like and how do they work if anyone knows? Just curious. the N* is running great since the HG's were replaced. An amazing amount of power and no overheating so far under any condition. I have my fingers crossed and I find that I am constantly looking down at the temp guage to see if there is any movement. I guess I'm still gun shy.

I can say I don't blame you after what you & others have been through.:yup:

blb
10-09-06, 08:02 PM
The overall head bolt length changed in 2000 model year simply due to the design of the new cylinder heads. Basic thread engagement remained the same...just the overall bolt length was longer in 2000 because the head bolt bosses are higher in the new heads. The thread pitch did NOT change in 2000...only the length....

So, seven model years of Northstars were produced without any changes to the headbolt threads in an attempt to reduce failures. Hopefully, we all agree on that.


Minor changes to maximize thread engagement were made thru 2000 and 2001 model years.....

If thread pitch wasn't changed, and length of thread engagement wasn't changed, please explain what was changed to maximize thread engagement.


The thread pitch was changed in 2004 to a coarser pitch thread for improved thread engagement. Bolt length remained the same as was changed to in 2000. The coarser pitch thread was concurent with the longitudinal Northstar engines in the rear wheel drive cars.

All of this is very simple to the naked eye if you just look at the parts....like someone who is working on them all the time might do........

Let's all hope this finally solves the issue.


blb......for someone who supposedly knows all about these things and "works on them all the time" and has supposedly seen "all these failures" you sure don't know much about the details or what headbolts go where......hmmm...

No need for personal attacks chevelle...I don't claim to be an expert by any means, and I never, ever claimed to "work on them all the time" as you stated. I do stop by this site from time to time because I like to learn as much as possible and I do turn a wrench from time to time, but not as a way to put food on the table. (There are easier ways to do that). I have seen literally dozens and dozens of Northstar headgasket failures over the years at a large dealership where a friend works. Some were failed before the first coolant change was due. It is both interesting and disconcerting to me that virtually the same failures have been occuring for more than a decade before a significant change has been made to correct the issue by GM. I appreciate any information or insight you may have on the subject.

Ranger
10-09-06, 08:07 PM
The shop owner desrcibed the Timesert as some sort of an attachment to the thread end of the bolts before they are inserted into the holes and they actually took the place of a helicoil. I didn't get to see one before the engine was re-assemled. What do they actually look like and how do they work if anyone knows? Just curious. the N* is running great since the HG's were replaced. An amazing amount of power and no overheating so far under any condition. I have my fingers crossed and I find that I am constantly looking down at the temp guage to see if there is any movement. I guess I'm still gun shy.

http://www.timesert.com

With the timeserts in place, you should never have to worry about it again, though I am sure it will take time to stop looking at that temp guage. Glad she is back and running fine.

MUGSANDLUKE
10-11-06, 05:17 PM
Still would like to know what the timeserts look like and how they work. Anyone have any answers please?

zonie77
10-11-06, 05:38 PM
timesert.com

Ranger
10-11-06, 05:57 PM
Still would like to know what the timeserts look like and how they work. Anyone have any answers please?
Didn't you see the link in post #20? Once you see what it looks like, how it works is pretty self explanatory.

blb
10-11-06, 08:13 PM
MUGSANDLUKE, Look at the picture at [url=http://www.timesert.com] as stated in the previous posts. After the existing, damaged, threaded hole in the block is drilled out to a precise diameter, the Timesert insert is threaded into the block to replace the damaged threads in the block. After the heads are installed onto the block, the headbolts are then threaded into the insert. Since the timesert material has better mechanical properties than the aluminum block, you rarely see a failure again, provided the correct procedure was used when installing the Timeserts and the correct touque is applied to the headbolts in the correct order. I hope this helps.

MUGSANDLUKE
10-12-06, 06:11 PM
Thanks for all the info guys! As it turns out the heads were replaced without the use of timeserts. According to my shop guys, who I trust implicitly, they said the bolt holes were pefect, they used new bolts supplied from GM, not aftermarket, and there was some sort of special material used on the bolt ends to insures proper fit and lack of a chance to losen on their own and it's not just Loctite. The ehads were re-surfaced and they guarantee the work for 12 months so I guess I'll have to see how it goes. The car runs great and gets much better mileage than it ever did, even cruising at 80 - 85+. Quiet and powerful. It screams off the line and is so strong that if I'm not careful the front wheels break loose in a heartbeat. No more head gasket problems so I'll have to keep you all posted. I wish they had used the Timeserts as I had discussed with them, but they said they did the job according to Cadillac Technical Service's instructions, and that's what the extended insurance was billed for and agreed to pay for. So we'll see. Thanks again for all the help and at least now I know what the Timeserts are and how they work. They seem to be a better design than the helicoils etc. If the problem occurs again I'll just sell it and buy another one from a newer year. Bye for now guys!

Ranger
10-12-06, 06:42 PM
"As it turns out the heads were replaced without the use of timeserts."

:eek: Trade it now Mugs while you can still get a decent price for it. It will likely fail again.

blb
10-13-06, 07:43 PM
"As it turns out the heads were replaced without the use of timeserts."

:eek: Trade it now Mugs while you can still get a decent price for it. It will likely fail again.

I agree!

zonie77
10-13-06, 11:31 PM
If there was no damage to any threads it should be Ok for a reasonably long time. If the heads torqued OK cross your fingers and keep driving it.

There were various discussions about uneven strength of the block, different coloration and grain on bad holes. Maybe a good block is a possibility. :yup:

MUGSANDLUKE
10-14-06, 12:46 PM
I'll keep running it for a while and see how it goes. Seems too be fine and I have the assurance of the mechanic, long time friend, thst it will be ok for aa long time to come. So I'm off with fingers crossed. if it fails again, we can always pull iut again and timesert it at that time. Still less expensive than buying another vehicle. Better the devil I know than the devil I don't. Could buy another one with the ssame headache. We'll see. To those of you who have said it will fail again I wonder how many of you have actually gone through this same scenario. I'll let you all know how it goes but thanks for the input.

Ranger
10-14-06, 04:54 PM
Mugs,
I have not been through it. I said that based on what I have read. I know that Barry94 over at Caddyinfo did his and did not know about Timeserts at the time. 10K later he had to redo it. Our old Guru always said that while not Timeserting it is not a guarranteed failure, Timeserting is 100% guarrantee that it will not happen again. Personaly, if I were going through all that work and expense, I would go the extra couple of hundred and the extra work to be sure. All that however is water under the bridge at this point and I hope yours holds. No one should have to go through this twice.

MUGSANDLUKE
10-14-06, 05:34 PM
I agree! I am dissapointed that the heads were put back in before I had a chance to grab them and have them order the timeserts. You're right though, water under the bridge and I'll have to see what happens. I've been told that if the block holes were in excellent shape and the original bolts were not lose that the chance is with the GM bolt kit it will probably be OK. They have guaranteed the job for 12,000 miles so we'll see what happens. I would still recommend using Timeserts to anyone that has this problem. I just can't force them to pull the heads again and do it all over. By the way, the only way to get to the heads on these things with any sorts of ease is to drop the engine out. Getting to the back head bolts is damn near impossible and will take forever while costing a complete set of your knuckles. My mechanic had th engine out in one day and back in in ine day. The dissassembly in between was easy since the engine was on the shop floor. I certainly wouldn't recommend that this be done by anyone that hasn'e had a lot of exeperience doing it. I was there in the middle of the job and it is an extremely disconcerting sight to see the entire guts on the floor. Good luck to anyone in this situationa and I'm sure there are many more out there with this same problem. It all comes doen to how long the job lasts. hopefully the bolts will hold with the GM kit. Let me know if any of you come up with the same scenario. TTFN

MUGSANDLUKE
10-14-06, 05:36 PM
PS to previous entry - I wonder if anyone has had experience with periodically checking the head bolt torque so this problem doesn't re-surface.
Just a thought.

Ranger
10-14-06, 05:42 PM
Not a good idea Mugs. The head bolts come with a Loctite thread sealer on them. Once installed and torqued to specs, they should not be disturbed again.

MUGSANDLUKE
10-14-06, 08:26 PM
Ahhhh! Good point. The material on the bolts is, according to GM, not just a regular Loctite, but something stronger and of a different material and heat activated as well. But your point is well taken. I stand corrected. I will leave well enough alone unless the situation is forced. Thanks for the reminder.

Tricky
10-17-06, 01:52 PM
Sorry to pour hot water on the thread( pun intended) .
Ive just opened up my wifes N* and number one cylinder had water in it.
Ive removed both heads though and the left, your drivers side, head was fine but on pulling all the bolts from both heads you can see were the coolant had been getting into the thread holes. All 20 bolts had crud on the threads from the coolant getting at them. Both gaskets had been seeping.
After pulling all the bolts there is no way I would return them or new ones into those threads in the block unless they have Timeserts in them.
The left head is fine but the right head has a fine crack or track in it coming from the edge nearest to the cam chain housing. Common fault on alloy engines running on the wrong percentage of coolant.
N* engines dont seem to be immune from it.

MUGSANDLUKE
10-17-06, 05:04 PM
Gee, and I was just starting to sleep at night again. Like I said, only time will tell. I was told the bolt holes looked good and the repair would last. Now it's up to good ole lady luck and the Caddy gods. Let them smile on all of us. My friends will cover the repair if they ahve to do it over again but it's just the time it takes. Thanks for the hot water anyway.

Tricky
10-18-06, 01:42 PM
Yeah sorry to scare you but you are right too.
Your bolt threads might have been fine and the bolt holes clean , so I didnt mean to worry you.