Yet another Exhaust Leak Question

Eagle_and_hawk · 01-13-2008, 01:42 PM

I have been searching and reading all the posts on exhaust leaks, but I don't see this problem.

I bought the 97' about 6 months ago with 42K miles and it did have the cracked manifold. I replaced the manifold with one from eBay, which did have the flex pipes on 1 & 6, and used the gaskets included. That might be problem #1 was using the cheaper gasket they included, but not sure. I put on the new manifold using the included gasket & o-ring for down pipe. At first it sounded better, but never as quiet as it should have been in my opinion. I did torque the bolts down properly and in sequence.

Here is the part I find strange that seems to be different from other leak; It's quiet the first 1- 2 minutes when it's cold, but then as it heats up, it sounds like a full blown cracked manifold. Since I only have 50K miles on it now, the new manifold should not be cracked and I am thinking maybe it was the cheap gasket.

Another interesting thing is if I am not accelerating for a minute or two, and then speed up, the first 5 - 10 seconds, it's quiet and then it's as if the leak opens back up and you can hear it the rest of the time. It's not as if it has to be cold to be quiet, just cool a little from not accelerating.

Any ideas on what this might be? Right now I plan on getting a Mopar gasket and using the copper spray, and installing it. Since the quality of the manifold may or may not be good, I might just go ahead and buy another one of know quality since I have to take it all back off again.

Zach571 · 01-13-2008, 02:05 PM

You're gonna have to look it over for the leak, there should be black soot around wherever it is leaking.

Zach571

carpekd · 01-13-2008, 02:16 PM

sounds like a gasket sealing issue since it does it when the manifold heats up and expands.

**Tractor Boy** · 01-15-2008, 02:54 PM

I am replacing the exhaust on my 98 tj. My mechanic says that you need to take off the intake as well and take them to a machine shop and have them both milled. That way, they match up with the gasket. That should solve the problem.

M.DURITZ · 01-15-2008, 05:11 PM

umm a cheap gasket is a big deal with manifolds. if you don't put the gasket and manifold on correctly, just perfectly, you will have a leak. I would get a better gasket and try your best to center it straight on with the manifold.

creaky70 · 01-16-2008, 08:06 AM

I put one of those EBay manifolds on my '99 TJ about a year ago. While the manifold looked quality, the gaskets that came with it were crap. I used Felpro and have had no problems.