: timing chain with engine in car

01-12-10, 09:21 PM
car the timing chain be reset on a 95 Eldo if the motor is still in car? is there room to remove the harmonic balancer and front timing cover?

01-12-10, 11:03 PM
By pulling the pass side wheel, you can definately pull balancer and front engine timing cover. It's not easy but doable. If you need to reset timing chain your in for a lot more than just the chain, as these engine are such that the valves get bent if your cam timing has jumped.

01-13-10, 07:59 AM
If you do a search, I posted previously how I did HG in the car. I only removed the bolts from the timing cover, there is enough room to get in there to release the tensioners without removing the balancer.

Mark C
01-13-10, 04:56 PM
What are you trying to do? They make a special set of pliers that reach down into the cam chain opening in the head to keep the tensioners compressed. Then you can take the camgears off the cams and reposition everything. If your just trying to move the cam a tooth or to, thats the way to go.

01-13-10, 09:46 PM
I read your post Bigtone. awesome write up. I'm probably going to do the head gasket repair with engine in the car. I also have plenty of time. I'm going to go with Norms' repair kit. the only thing that concerns me is that timing chain tensioner issue but your write up gave me the confidence to do the job. hope you don't mind if I send you some private messages if I run into a problem. I plan on starting job when weather warms up. I read that I could stick a block of wood by the tensioners to keep them from getting tighter. do the cam gears come off the cam easy or do they need to come off with a puller?

01-14-10, 08:22 AM
The block of wood performs the same function of the tool mentioned above. To be honest, I think I had enough room to reach thru the head opening to release the tensioners. I ended up opening the timing cover just to replace a plastic guide I broke when removing the head. The gears do come off easy. Any questione shoot me a PM.

02-04-10, 07:57 AM
Got a question, Just did inserts in the head to replace the head gasket... Made a Mistake in taking apart the heads, should have put the engine top dead center before tearing down, but unfortunately my kid started the tear down and did not do it.. well anyway put the heads back on, I had tie wrapped the chains on the sprockets at the top and put a bungee on em to keep tension, well the chain must have still slipped a few teeth, but am not sure if it did or the bottom end turned... once the heads are on how can i check to see if the timing is correct? If I put at top dead center on number one piston are there indicators on the heads? and where do the align? I am just thinking the chain slipped down the bottom as if The bottom end did turn you would think both sides would be off the same amount...Thanks for any input.Also what is the torque for the head bolts? Is it the same with inserts as without??? it is a 95 Northstar....

02-04-10, 03:40 PM
The chain for the rear head slipped on mine too, even though I had it bungeed down. I had thought about that ahead of time, that is why I stopped and locked the engine at tdc #1 before I disassembled, just as extra insurance, and I was glad I did that. To be honest, you need to set the timing up from scratch now, but you cannot turn over the engine with the heads installed, I believe you will have valve/piston contact. What I would do is remove the camshafts. Not really hard at this point to do that. Then I would rotate the engine and stop it at TDC #1. I used a depth dial indicator down #1 plug hole to get there. Then install the cams with the marks at exactly 90 degrees to the valve cover flange. If you are anal like me you could then rotate the engine by hand to ensure no interference, then perform a cranking compression test and ensure that the front and rear cylinders are close to even. If you are off a tooth, I would think you would see a noticable difference in the compressions front to rear.

02-04-10, 03:57 PM
The head bolts are turned to a certain torque, then a certain # degrees, in three steps. Don't quote me, but it's something like 27 ft pounds, 60 degrees, 60 degrees, 70 degrees. Better check the specs on that

02-04-10, 06:01 PM
I would reset the timing from scratch, by pulling the camshafts. Before you reinstall the camshafts, run a leakdown test and make sure your valves are sealing adequately (a bent valve would show a very severe leak, at least 40% leakdown or more depending on tester).

02-04-10, 07:13 PM
Thanks for the replies, where are the marks on the cam exactly,I am assuming they are the pins at the end???and you say 90 deg from the flange, so that would be facing up 90 deg right? want to see the marks before I take off the cam... And where do I find the specs for the head torque.. I really do not think the bottom end moved but better safe then sorry Thanks again for the help... Oh and isn't the Northstar a non interference engine?? so could I not turn it by hand and check to see if at TDC that the marks are at 90 deg???

02-04-10, 08:06 PM
Definitely interference - very much so. I seem to recall I installed and turned down the head bolts on the right bank finger tight, before I realized I had forgotten to orient the cams properly...or maybe it was the crank. Well, anyway, I tried to turn the crank by hand to the proper position, very gingerly, but the valves hit pistons and locked up the engine, so I had to back off the head bolts and lift the head off the block a little to gain the clearance I need to align everything. It may be possible to turn cams or the crank partially, but you will not be able to turn anything 360 degrees without hitting something. If you do need to make a small adjustment, I don't think there would be any harm in trying to do it like I did, but just be careful, and stop if you meet any resistance.

02-05-10, 09:03 AM
Going to go at it today, have the day off if any one has any input I will be looking it threw the day, doe these torque specs sound right?

In sequence, torque all bolts to 30 ft.-lbs.
In sequence, rotate all bolts an additional 70 degrees.
In sequence, rotate all bolts an additional 60 degrees.
In sequence, rotate all bolts another 60 degrees

How can I tell exactly what 70 Degrees is? or 60 Degrees? never did a head that required degrees??


02-05-10, 10:59 AM
A hex head bolt has 6 points - 6 x 60 (degrees) = 360 degrees. Eyeball it with a magic marker tickmark.

02-05-10, 11:40 AM
I used this angle gauge - I don't recommend this particular one, but others here have used other ones that i think might be better:


02-05-10, 12:07 PM
Thanks... Going to run out and see what I can find...

02-06-10, 11:41 AM
Ok never got to it yesterday, but today is the day.... What cylinder is #1?? and the marks on the Cam is that the pins that hold the sprockets off? are those the marks that need to be at 90 deg???? Thanks...

02-06-10, 04:53 PM
#1 is passenger side rear bank. Yes, the pins are your mark . Use a square, believe it or not if you do it by sight you can be off a tooth. I heard that happen to a few guys on the board here.

02-06-10, 11:47 PM
Ok Had some trouble, can not get harmonic balance off.. Tried two impact Guns but bolt would not come off... So had to bring up #1 to what I figure is TDC I hope... Used a square will probably get it all back together Sunday, Then I will see if it is out of time... If so looks like I will need to get a bigger gun I guess to get the balancer off to open the timing cover...

02-07-10, 07:27 AM
If you read back all the answers to this post, you'll see that you can get in there without removing the balancer. I posted pics of doing mine with the balancer installed. Do a search.

02-08-10, 06:13 PM
Oh I did it I was able to depress the guides without even removing the timing cover, but I was under the impression that there was a timing mark on the shaft of the balance, so I wanted to use that.. I depressed the clips with a pick and long serpentine belt bar, then slid the guide in and depressed that to hold it down did not have a problem with that, but did you just use the piston to find TDC? just seems like you could be off a tooth or so doing it that way, seems to have come out fine, but getting the piston at TDC was sloppy and would have preferred to line up marks, or were you able to see them the way you did it??? Well the Car is back on the road, but since I never seen this car run before the head fix, what is normal temps? It runs at 199 Deg driving, that was on the regular streets as well as Highway, sitting at a light it went up to like 212 deg. Is that Normal? I have read these cars run hot... Thanks guys and Gals for all the help...

02-08-10, 06:25 PM
Yours is a 95, right ? (These engines do NOT run "hot": they run at design temperature.)

This is a pretty close explanation - some Northstars use slightly different programming, but here goes: If some A/C function is set (defrost, too) the compressor runs as necessary and the PCM commands fans to SLOW, so the coolant temp stays fairly constant - 190's. Without A/C (ECON) and/or some defrost command, fans are controlled by the coolant temperature sensor, going to SLOW at about 224 degrees and FAST at 236. If you're in traffic, the temp will slowly creep up to about 224, fans come on, and the temp drops to about 212, fans OFF. This cycle repeats as long as you're stuck in traffic with no A/C function set.

The thermostat is designed to begin opening at 188 and be fully open at 206, so the 190's are perfectly normal - some Northstars run at 206 - 210. Normal.

02-08-10, 07:56 PM
Yep - normal. Congratulations on a job well done!

02-09-10, 10:19 AM
If you read back all the answers to this post, you'll see that you can get in there without removing the balancer. I posted pics of doing mine with the balancer installed. Do a search.

Hey bigtone, Is it possible to send me a PM, I got a quick question for you. I tried to send you one but it would not allow it to be sent. thanks

02-09-10, 03:58 PM
Sure, try bluesman86@hotmail.com

02-12-10, 08:55 AM
Ok new problem or is it same problem??? My kid been driving the car to work every day since we fixed it, down the turnpike about 75 miles each way so 4 days at 70 to 75 mph 150 miles a day without trouble, the temps have actually lowered since I first posted, been running in the low 190's and at stop lights or traffic has not been over 210 so he says.. Well he called me this am and says he is getting a low oil pressure warning, I told him to pull over shut it off and call AAA, and have it towed home to my house. Any Idea what I should be looking at? before it gets here so I have a start point? Thanks..

02-12-10, 10:05 AM
IF you removed the crankshaft harmonic balancer (pulley), that unit bears on the oil pump and is the friction drive for the center oil pump gear. There is a specific high torque sequence for tightening the balancer bolt. If not done correctly, the oil pump "slips" and you lose oil pressure. To do the torque sequence you need to lock the crankshaft by either removing the intake manifold and starter and locking the flexplate gear there (special GM tool) or you might be able to lock it by removing the cover plate under the engine/transmission joint - underneath the transmission case. That also exposes the ring gear.

If that install was done 'by the book", then the other suspect is the oil pressure sending switch/sender/sensor at the top side of the filter adapter - these sometimes fail and give a false reading. AC Delco only, either a dealer or www.rockauto.com. Inconvenient to replace, but can be done in an hour.

Hopefully, after your repair, the oil level has been checked often and not overfilled......

02-12-10, 07:19 PM
Think I may have found the problem, removed the oil pump and opened it up there is a small channel that runs along the edge, I am assuming that is the priming channel, well that had a bunch of junk in it... Cleaned it out and now reinstalling it, does any one know the torque specs for the harmonic balance? My manual is for a 95 but says for a 96 on the torque... Says something about 96 went to a smaller bolt and new specs are... But this is a 95 and my manual is for a 95 and I have the large bolt...

02-12-10, 08:02 PM
Not 100% sure - maybe 38 foot pounds, plus 1/3 or 120 degrees turn? Someone else will chime in, but that is pretty close. That bolt was REALLY hard to loosen - I messed up the head, so I bought a new bolt from Cadillac and put some light oil on the threads and it was really fairly easy to install - so much so that I thought maybe I did it wrong and loosened it and did it again, but with the same result. I have always had good oil pressure with no problems since restarting the engine - I just followed the manual's procedure to disconnect the power leads to the ignition module and crank over the engine without starting for...I think it was 30 seconds - something like that. It did take a few minutes to get oil up to the lifters and 100% quiet them down, but I had my oil light out immediately upon startup.

02-12-10, 09:32 PM
Thanks... Found it was 46 pounds and 120 deg... will follow your advice about cranking with no spark for 30 sec... putting the oil in now and will let ya know..

02-15-10, 08:07 PM
OK this car is driving me nuts... put it back together, same problem, so I took it all apart and looked at the oil pump again, and seems the relief valve was sticky, don't know how I missed that, but anyway, I wanted to look at the timing again so I removed front cover and had bottom marks lined up and front was right on, the rear a bit more difficult had to remove the motor mounts in front as well as under the front, dropped motor and then was able to get cover off well back seemed to be off a tooth, well adjusted that put it all back together started the car, and now I get trouble code for the cam positioning sensor, and car runs like crap, is trying to adjust.... The sensor is plugged in on the side, is there anything I missed??? Don't know if oil pressure is fixed as I won't run the car with it like this.... Help.... It plugged in and does it run from there to the coil pack???? can I read a voltage??? or should I be looking for continuity to make sure I did not pinch the wire??? Any thoughts???

02-16-10, 06:40 PM
Did you install the correct gear? I think maybe there is only one that has the needed pin on it?

07-28-12, 08:17 PM
if tensioner is released can it be compressed from cam chain opening in head

07-29-12, 10:48 AM
The chain tensioners have ratchets - as wear/stretch progresses they keep their automatically adjusted tension (less the slight hydraulic boost from running engine oil pressure) so they must be removed and manually retracted by tripping the tensioner latch and squeezing the shoe back into the tensioner.

Maybe, just maybe, if you make some long, thin strong tools you can perform laproscopic surgery through the cam openings, but I doubt it. Pull the harmonic balancer (lock the engine from turnng) and remove the timing cover. Special torque sequence on harmonic balancer bolt..........

There are special procedures for retaining chain tension, thus preventing tensioner extension, when removing the cam chain sprockets. It's in the GM/Helm service manual and is also somewhere in the pages of Discussions: Cadillac Tech Tips. More chain and timing illustrations in my albums - click my username, open the profile. 2 albums, 6 pages, in the left column.

08-02-12, 11:27 PM
there are 6 gears in this engine, 3 tensionsers, 3 chains, and 6 timing marks. Getting it all right with the engine in, as you are finding out, is almost futile. I also believe I read that you can rotate the engine 16times before ALL the marks line up perfectly (this is including the intermediate shaft above the crank which the cam chains loop around). I wish you luck

08-03-12, 09:49 AM
It takes 14 or 17 (I forget which) complete revolutions to have everything (chains, too) line up as timed from 0. But, the cams and crank will go into original time once every 2 revolutions if you stop on #1 cylinder TDC before the power stroke.

v Intake - ^ compression - v power - ^ exhaust

08-04-12, 01:24 AM
14 revs to get everything lined back up.

02-21-13, 11:03 PM
Hi....Rob from Santee.............I've found a way to get the dampner off in the car........on the 4.6 ...northstar.....eldo...........drill a hole in each of the three legs othe the wheel....tap each one to 3/8 14......put on your puller .......use a short bolt..........and presto.......you'll end up with it in you hand.........