Exhaust Manifold Gaskets

[JPVortex]

Hey folks, just replaced exhaust manifolds with gaskets on my 02 Suburban, and they leak still..... Not as bad as before, but they do leak. For gaskets I ran an MLS gasket from a brand called "Michigan Motorsports", they had good reviews, but still both leak already. I did notice when doing the job the head surface where the manifolds sit didn't look the best. There was some pitting here and there, and I wonder if that's contributing to leaking again.

So now I'm in a debate, do I buy Genuine GM MLS manifold gaskets and try those or do I try running the graphite gaskets that came with the manifolds I bought? I feel the graphite could work decent in my spot because it conforms and bends more, which could help with the pitting on my head surface.

Thank you!

 

[Scottydoggs]

copper hi heat rtv might help out with the pitting, but i bet studs vs them crap manifold bolts helps the most.

studs and nuts just clamp so much better.

 

[JPVortex]

copper hi heat rtv might help out with the pitting, but i bet studs vs them crap manifold bolts helps the most.

studs and nuts just clamp so much better.

Thanks! Studs and nuts are already done… haha! Decided that I did not want to deal with bolts ever again lol. Made lining everything up a breeze too.

 

[JPVortex]

copper hi heat rtv might help out with the pitting, but i bet studs vs them crap manifold bolts helps the most.

studs and nuts just clamp so much better.

What would you do for a gasket type? Not sure about using the copper rtv on MLS. Thinking I may try the graphite ones with some spray copper rtv

 

[Scottydoggs]

you really cant do better then the factory metal ones. ive reused them when installing headers on cars.

 

[JPVortex]

you really cant do better then the factory metal ones. ive reused them when installing headers on cars.

Ok appreciate the feedback! Think I'll give the GM Genuine MLS gaskets a try with some RTV.

 

[Scottydoggs]

Ok appreciate the feedback! Think I'll give the GM Genuine MLS gaskets a try with some RTV.

id only do a very light smear of the rtv. might also want to make sure the manifolds not cracked in the body of it, or warped along the flange.

 

[JPVortex]

id only do a very light smear of the rtv. might also want to make sure the manifolds not cracked in the body of it, or warped along the flange.

they didn't look cracked or warped, they are brand new, although cheaper ebay ones. The leaks are very very small.

 

[Scottydoggs]

they didn't look cracked or warped, they are brand new, although cheaper ebay ones. The leaks are very very small.

you could run a straight edge over the flange to check. china made stuff is not always so good.

 

[Marky Dissod]

If you've replaced the gaskets and you STILL have a leak, it's likely there's a surface that needs to be smoothed true.