Cometic gaskets leaking?

[Dreamcar86]

Anyone ever have problems with cometic head gaskets leaking oil? This engine has less than a thousand miles and to the best of my knowledge there are no signs of the gasket being blown. Any thoughts appreciated.

 

[hemi8]

Oil drainback from the heads, it hits the engine deck, puddles up then flows into engine but it is always puddled sitting on the deck looking for a way out. I have seen some place a strip of RTV at that area on the block so the oil can't work its way around the head gasket edge.
Mike

 

[Dreamcar86]

Oil drainback from the heads, it hits the engine deck, puddles up then flows into engine but it is always puddled sitting on the deck looking for a way out. I have seen some place a strip of RTV at that area on the block so the oil can't work its way around the head gasket edge.
Mike

Uh Oh! Looks like I am going to be removing the engine again and making a repair. Do you think it is a good idea to stick with the Cometic's or go back to the stock gaskets? I have know people who have had 10-0 cars with stock head gaskets and swear by them.

 

[SNOWBIRD]

Befor you remove engine ,check rear of intake both corners ...they can be fixed with much trouble

 

[SNOWBIRD]

without much trouble

 

[disco stu]

I have a thread somewhere about installing cometcs I think. I'll see if I can find it when I get to a computer. I remove the rivets, separate the layersand coat with coppercoat. Retourque is critical. I do it on a stand with a adapter I made and heat with beat guns until the deck area under the block is an even 200 degrees. I usually have to do 2 or 3 cycles before it stops taking torque. They work, but u gotta do it right.

 

[turbo nasty]

IMO they are going to leak coolant unless you follow these steps and most will still seep oil.

1.Drill the rivets out.
2.Spray the crap outta all the layers with copper coat
3.Retorque
4.Use seal tabs

As far as the oil seeping I have been tossing around using permatex #2 that stays pliable for the oil drian areas

 

[SNOWBIRD]

I did exactly what turbo nasty did ,no leaks at all.retorqued once after 24 hours,you would be surprised how some of the stud nuts lossend up.

 

[Dreamcar86]

Thank you guys, this thread has turned out to most useful. Only wish I would have asked the question before assembly but oh well live and learn its a Buick.

 

[vacuum 6]

I'm 99.9% sure one of mine leaks oil (PS). Drips off the head to the trans lines and onto the dust cover. I have not done a thing less place cardboard under the car. Car been raced for 3 years now.

 

[Dreamcar86]

I'm 99.9% sure one of mine leaks oil (PS). Drips off the head to the trans lines and onto the dust cover. I have not done a thing less place cardboard under the car. Car been raced for 3 years now.

That is the same side as mine and it is leaking in the exact same spot.
Looking back on this I probably should have stayed with the factory style gaskets. My car is a high 10, low 11 second car that most likely did not need to move toward the cometics in the first place. Live and learn what can I say.

 

[Jerryl]

It is VERY uncharacteristic for a Cometic HG to leak oil, unless something major is going on, since the gasket never sees "oil pressure".
If it leaks oil out of the cylinders, there is also a compression leak, and there are bigger issues.

Typically, the oil you see will leak from the lifter valley, down the back, on the gasket, giving the appearance of a leaking HG.
You should be able to re-torqued Cometics without head removal anyway, if they are not hurt.

 

[disco stu]

It is VERY uncharacteristic for a Cometic HG to leak oil, unless something major is going on, since the gasket never sees "oil pressure".

They will. First time I tried them they leaked on the stand after priming it. Oil draingback was wicking throught the layers. New heads, deck blocked, installed dry.

 

[Jerryl]

They will. First time I tried them they leaked on the stand after priming it. Oil draingback was wicking throught the layers. New heads, deck blocked, installed dry.

WOW! :redface:
Where do you think the oil was leaking from?

 

[turbo nasty]

It VERY common for them to seep oil

 

[vacuum 6]

It VERY common for them to seep oil

They are sweet.

 

[8urV8]

I have a thread somewhere about installing cometcs I think. I'll see if I can find it when I get to a computer. I remove the rivets, separate the layersand coat with coppercoat. Retourque is critical. I do it on a stand with a adapter I made and heat with beat guns until the deck area under the block is an even 200 degrees. I usually have to do 2 or 3 cycles before it stops taking torque. They work, but u gotta do it right.

Yep what John said I did the same thing because of the cometic horror threads. But if you do them right these are very good gaskets some say yes and other say no.

 

[vacuum 6]

I have a thread somewhere about installing cometcs I think. I'll see if I can find it when I get to a computer. I remove the rivets, separate the layersand coat with coppercoat. Retourque is critical. I do it on a stand with a adapter I made and heat with beat guns until the deck area under the block is an even 200 degrees. I usually have to do 2 or 3 cycles before it stops taking torque. They work, but u gotta do it right.

Can you post pics of the adapter you made to simulate heat cycles?

 

[R.I.P.92Rolla]

i am about to throw a pair of ported heads on my car...the car is pretty much stock and will probably get a turbo upgrade and downpipe soon but nothing crazy... I was told to go cometic...but it seems like a decent stock set would do the trick...is cometic to much of a hassle for me since it wont be a complete race car, i like to drive it in the summer and maybe take it to the track one or two times

 

[NC87GN]

Myself included I know 4-5 buicks locally, that leak some oil, using cometics. Compression leak down shows fine. They leak between the layers. I will go back to a composite style next time I rebuild. I do know some that have had good luck but I did not take the time to put a fine microfinish on my block and heads and drill out the rivets. I did use copper coat, top and bottom, but not between each layer. Other than the oil leak engine runs great. Just my 2 cents..

Mike Banas
87Gn