Problem with Cometic Headgaskets...

[19TTA89]

Long story short....They seem to be pushing oil in between the actual layers of steels....when the car is running,and up on a lift...You can see the oil slowly form a drop along the edge of the gasket between the 3 and 5 cylinders......it then runs along the outer edge of the gasket,and drips onto the header flange..(I checked the torque specs..And everything was fine..)

The motor has just been rebuilt....The Heads are aluminum GN1's...THe block was decked and the smoothed to the correct RA for the Cometics...Along with the heads..The Builder is Familiar with the cometics,He uses them in alot of BB Chevys..

My builder said he has seen this problem once before in a pontiac...He said after they made a few passes with the car the leaking stopped completely...(Once the rings seated...)

My question is...Did anyone else on this board ever have such a problem with these gaskets????If so,Did the rings seating cure it...

Also...What other gasket are people using with GN1's????I am thinking about going back with the FelPro's,I never had any problems with them...But this is my first aluminum head LC2...

Also,What Plugs are people using with the GN1's???There were Autolite 103's in there when I got the car,But I am not sure if that is the correct plug or not...

Any help would be appreciated.....I am planning to rip this thing apart again tomorrow,And go with diffrent gaskets...If these things are leaking at an Idle...I couldnt Imagine them sealing enough to hold 20-25 psi of boost...

Thanks,Shawn

 

[S2V6RACER]

Don't know about the Cometics, but a 104 for the street and 103 at the track should work good.

 

[SITHV6]

wow...probs with cometics? besides the one post I've seen with someone going a little nuts with the RJC 1400GE silicone blocking up the oil and water passages after install....ARE the RJC double steel stacked HG getting good reviews so far? *has a set installed on a new rebuild and happens to be sweating bullets reading the subject matter*

 

[turbosam6]

I'm still trying to figure out how you have a leak at the head gasket and it drips on the header flange higher up? Are you sure its not the valve covers leaking? Mine leak (the vc) and it drips off the head gaskets where the rivets are.

 

[19TTA89]

Originally posted by turbosam6
I'm still trying to figure out how you have a leak at the head gasket and it drips on the header flange higher up? Are you sure its not the valve covers leaking? Mine leak (the vc) and it drips off the head gaskets where the rivets are.

Ok..should of been a little more specific.....Its the Flange that the Crossover pipe mounts too.....

I spoke to Tom at champion Today....He really doubts that the oil is getting under the gasket....He thinks that it is running off of the Intake somewhere and coming around the edge of the gasket...I am really going to do a real good checking over tomorrow nite..Along with pressure testing the cooling system..Just to make sure it isnt distilled water mixed with a Bit of antifreeze that Im seeing.

Either way Im going to Retorque them and hope for the best...If I dont find any other problem..

 

[J Banning]

Shawn, any updates?

We're having the same problem on a car that we're working on right now except it isn't oil... it's the water from the cooling system. Everything is fresh. The engine probably hasn't seem 3000rpm, and has still to leave the garage (0 miles).

Thanks,
-Banning.

 

[19TTA89]

Banning,

The problem I had back then turned out to be the Intake gasket(Rear)....Leaking out of the corner of the gasket...then leaking onto the edge of the headgasket...And running around the gasket toward the front of the motor,Where it would hit a raised part of the head casting,And drip down on the header.

It was not easy to find...had to put dye in the oil,And use the uv light/Glasses...And it was still tough to locate.

Shawn

 

[disco stu]

http://www.turbobuick.com/forums/showthread.php?t=161092

 

[NC87GN]

I've seen it leak oil through the layers, on a cometic gasket, on my personal car. Used the engine oil die to trace the leak. However in cometics defense I did re-use the gasket twice. I work of caution if you ever plan to re-use these gaskets is to check the spring steel height thickness and make sure you have .010" minimum height around the combustion chamber or there is a chance you will have problems. HTH

Mike Banas
87GN

 

[gn4u2c]

gm cooling system tabs 4 of them stopped my water leak at the gasket.