I have a tiny bit of an exhaust leak on my new system. I have the original W//X/Y/Z manifolds on there, and the guy who put the system on said that because they are in not the best of shape, it may leak some, and if it does I can just put some "muffler mud" on it. Well I noticed today that there is a "puff puff" coming out of my pass. side manifold where the flanges meet. What ill effects, performance wise, could be caused by this? It is a tiny leak, maybe a quarter inch wide....anything I should be concerned about? Or should I treat this as a vacuum leak and fix it like everything else on the engine?

 

Why didn't he just use exhaust sealer when he put the flange together to begin with? Did he say that before or after the job was done?
Sounds like CYA to me if afterwards.
They recommend sealer for that joint somewhere in the literature.
You would have to drop the pipe and put sealer on the flange then put it back together to do it right.

 

I would fix it. Exhaust leaks are annoying.

 

I do not think that would affect performance much, but fumes could be drawn into the car while driving - not good for the occupants. Get it fixed before cruising season.

 

X2 on that.

 

Is it at manifold to pipe joint or manifold to head joint?

The factory did not use any sealer or gasket on the manifold to head seal. I understand there was a graphite compound applied during assembly to seal the machined surfaces. I've never been lucky enough to have one not leak if I didn't use a gasket.

If it's at the pipe connection and the manifold surface is gouged or pitted, odds are you'll have to use some muffler cement or a doughnut gasket to stop it.


A leak that close to the exhaust valve could possibly cause a burned valve.

 

I always heard that an exhaust leak close to the manifold/header could cause a burnt valve when I was growing up. Keep in mind, I don't DARE do much of anything mechanical to any of our Oldsmobile's; body work, OK. End of story.

 

The leak is at where the downpipe connects to the manifold. Yeah it kind of made sense that he would have put the mud on there in the first place, but he is a friend of my sisters fiancée and I got the system for an extremley good price, so I didn't make a big deal about it. I will just put some mud on it and seal it up. I just wanted to make sure that while I was into the engine fixing the vacuum problems that this leak wasen't going to be throwing me off too much.