'79 Exhaust Manifold gaskets replacement

[Peter G.]

My '79 has a exhaust manifold leak on the drivers side of the engine. Would like to know if anyone has changed these gaskets before and how difficult is it? A "Corvette Shop" has already taken the manifold off and put it back on without the gaskets saying "that they are not supposed to have gaskets", but it leaks worse! So the rusty bolts should come off again without much trouble.

Thanks in advance for your responses.

[Joe L.]

Re: '79 Exhaust Manifold gaskets replacement

Peter------

No gaskets between the exhaust manifold and cylinder head were EVER originally used for any Chevrolet V-8 engine, except those few originally equipped with tubular steel exhaust manifolds. If your situation requires gaskets to prevent leakage, then you must have a warped or distorted exhaust manifold(s). The fix is to take the manifolds to a machine shop and have them surfaced to re-establish a flat and true surface. Afterwards, re-install them without gaskets and there should be no leaks.

[Peter G.]

Re: '79 Exhaust Manifold gaskets replacement

Joe, thanks for the response.

That is what the Corvette Shop wants to do, but I am concerned that may not take care of it. Would it then be possibly the head itself that may need planning? Can you plane a head to make it flat? Or worst requiring a new head? Since it had gaskets already on, that maybe this senario could have already been played out?

Peter

[Joe L.]

Re: '79 Exhaust Manifold gaskets replacement

Peter-----

Rarely, if ever, is the problem associated with warpage of the cylinder head manifold mating surface. However, I wouldn't rule out the possibility 100%. The cylinder head surface can be machined flat, but the cylinder head would need to be removed from the car to do it. I'd get the manifold(s) done first. They can be chacked with a precision straight edge prior to machining to confirm the problem. However, sometimes doing this check on a manifold surface can be problematic. So, I'd have them machined regardless. This should cost about $25 per manifold.