Exhaust Leak

[390xlt]

I've got an exhaust leak on the right side of the engine, but I can't tell exactly where it's coming from. Placing my hand right behind the manifold reveals that it's coming from somewhere in that area, but I can't tell exactly where. My first assumption was that the doughnut between the manifold and the pipe was shot, so I replaced that, but I'm still getting the same issue. In theory, I feel like I should be able to pull the manifold off, figure out what's wrong, then put it back together -- either with a new/repaired manifold or a coat of copper rtv -- and call it good. In practice, however, there are a million things that could go wrong. So here's my question: if I can get the manifold off without breaking any bolts, how big a can of worms am I getting into? Alternately, what else should I check before taking anything apart?

On a related note, I really do need a new exhaust system, but I lack the time and equipment to bend one up myself. Anyone have a ballpark figure for how much I should save up for a simple system? Nothing fancy; I'm thinking just manifolds*, two regular steel pipes, and a couple of glasspacks. And if anyone knows a good muffler shop in Atlanta, I'm all ears.


*I'd love to go to headers, but I'm pretty sure my current financial situation isn't going to allow for that.

[Lee]

Hi,
Are you running Headers.... which are prone to leaks...Or the original manifolds?

With my headers I was replacing gaskets regularly.... Tried all different types... With and without different RTVs.

What solved my leak problems permanently were thick solid copper gaskets and they are reusable.

Lee

[Ohiotinkerer]

Sounds like you have the same problem i had - had 1 port is on the p/s manifold started leaking due to age/ warping.....it's not a hard problem to fix if you have a good machine shop in your area. I pulled mine and had them ground smooth to get everything back flat and reassembled them with a set of Remflex gaskets - they are a thicker type that will help seal everything up since these were pretty much metal to metal deal from the factory and I didn't want to pull the heads to have them machined also. Worst case is they are too warped or blown thru to fix (mine were borderline no good) so you could find a good used set, aftermarket new set, or switch to a set of Sanderson headers - but as you said headers aren't cheap! If I remember right i had $100 in getting the manifolds fixed and the gaskets.........

[390xlt]

$100 is a lot, but not as bad as it could be. I've been soaking the bolts in an acetone/atf mixture, so I'll keep doing that until I can't put it off any longer, then take a wrench to them and hope for the best...

[tsherry]

I used a piece of rubber tubing, held near my ear, and the other end near the manifold. I was able to find out where it was leaking pretty quickly. Then, replaced the gasket with the copper version mentioned above. Three years on, no problems.

[basketcase0302]

Exhaust leaks are always much easier to pinpoint when the engine is cold.
Crank it up and quickly feel around the manifold for the leak.
I was never a big fan of the FE "log manifold" but I'd budget for a new one as I've seen so...many guys here (including myself) finding them cracked once they got them off.

Robert (Duckryder our moderator here) is in Atlanta and might know of a shop there close to ya'll?
Real...good investment to have a new system put on a as most shops honor a lifetime warranty.
I took my then 5 year old dual with flowmasters off of my 79' F-150 and put it on my 71' F-350 and was very pleased with it.

[71cc]

Shop vac "out" blowing in exhaust pipe. Then go get a cigarette..

[390xlt]

I ordered some of the Remflex gaskets, so hopefully those and maybe a little machine work will solve the problem. Anyone have any experience with or have any opinions on Heartthrob exhaust?
http://heartthrobexhaust.com/manifolddualkits.htm
Looks like they've got a kit that should bolt right up, but I'm a little leery of something that seems that easy.