Exhaust leak 75 L48

Thanks Paul...will do.

Scott

Also, make sure it's not a cracked manifold...they can be hard to detect at times, depending on the location of the crack.
IMHO, the best exhaust gaskets you can use are header gaskets, believe it or not. Get some name brand header gaskets, and soak them in water for a few minutes(2-3 minutes). Then bolt them on before they dry out. Tighten them down really snug. Being wet will allow them to compress around the exhaust ports. Once you start it up, and the heat from the exhaust dries them out, they'll be there, with no leaks ever, unless the bolts back out for some reason. I'll usually put a wrench back on them after running it for 15-20 minutes, just to be sure they're tight. Werks every time fer me...

I agree with Adam.  Wet header gaskets from a brand name source work best.  They don't look exactly stock, in case that is a problem.  I would suggest that before you take anything apart, you stuff a rag in the end of the exhaust so it creates more back pressure.  You might have better luck finding your leak.

Larry

Thanks Joel and Larry, Vettespecialties. I have alredy tried the rag trick. It made no difference. I will do a thorough inspection of both manifolds once they are removed. I certainly don't see any obvious cracks. Thanks to all for the excellent suggestions. If the weather is good this weekend, I will get er done.

Scott

If you take the mirror, and check with the vette running it will sometimes be enough to fog up the mirror, help to find cracks.

Or, do the rag trick, but dump a little tranny fluid thru the carb....and watch where the smoke comes out...

Well, I got the passenger side exhaust manifold gasket and valve cover gasket done tonight. I used the new Mr. Gasket copper exhaust gasket with the raised sealing area. I used a new style rubber valve cover gasket by Fel-Pro. The passenger side should be the most difficult because the AC compressor had to be moved aside. I'll start the driver's side in the morning. Thank you all for your great suggestions.

Scott
ranger32008-11-14 17:31:55

Scott, that's great, I'm sure it'll work out for you

I completed the project this morning. New exhaust manifold gaskets and valve cover gaskets. No more leaks. Took her for a ride, then re-torqued everything. Sounds like it should and no more smell of leaking oil on the manifolds. Back like it should be. Thanks to all.

Scott

It will be nice not having that oil smell, or exhaust leak sound. acplus2008-11-15 17:53:43