Exhaust Manifold Leak Again
 

I just replaced the gasket about 2 months ago now it seems to be leaking again. Any ideas why they would go out again? Too hot? warped manifold?

Re: Exhaust Manifold Leak Again
 

Weak motor mounts? A flexing power/drive train due to bad mounts may even crack exhaust manifolds. Worth a look...

Re: Exhaust Manifold Leak Again
 

Make sure manifolds are flat, surfaced. Buy GM stainless exhaust gaskets, use new bolts, no leaks, Ron

Re: Exhaust Manifold Leak Again
 

Some dude recommended Nord-Lock washers at work for some other application...I used them in my goofy integrated head straight six when the gasket blew out...I don't have that many miles on it, but so far so good. I think if the bolts start to loosen, then more heat gets into that part of the joint, cooks the gasket, then the joint gets bigger, more heat passes by, until the gasket is cooked and blown out. The keys are flat mating surfaces, and keep a tight clamp between sealing surfaces.

Re: Exhaust Manifold Leak Again
 

Are you talking about the gasket between the exhaust manifold and the head, or between the exhaust manifold and the exhaust pipe?

I quit trying to get a gasket to live between the manifold and the head. As long as the surfaces are clean and flat, the cast iron manifold will expand at a very similar rate to the cast iron head and it will not leak.

If you're talking about between the exhaust manifold and the exhaust pipe, you have to make sure that the mating surfaces are clean and straight, and that the proper gasket is being used. Some have a collar and some don't. And of course there are different diameters.

On my 1986, I've kept the vacuum operated valve in the exhaust to assist with quick warm-ups, so between the cast iron exhaust manifold and the cast iron butterfly valve assembly, there is no gasket and I've had no problems in 15 years.

Re: Exhaust Manifold Leak Again
 

I'm talking about between the exhaust manifold and the head. I used the paper/aluminum gasket. I'm going get the me all aluminum gasket this time.

Re: Exhaust Manifold Leak Again
 

i've never used a gasket between the head and a stock manifold without problems. Matter of fact only leaks there i've had is on ones the PO used the gaskets.:lol:

Re: Exhaust Manifold Leak Again
 

QFT.

Don't run a gasket between cast iron heads and exhaust manifolds.
:clap:

Re: Exhaust Manifold Leak Again
 

Well it wasnt the exhaust manifold it was the doughnut on the exhaust. :)