legacycentral bbs

Ever since I installed my 3" exhaust, Ive occasionally smelled exhaust. Figured nothing much about it, but its finally gotten on my nerves. Went and bought a new 3" gasket and went to install it on the car today, knowing that the leak was coming from where the DP joins tubing under the chassis.

After I pried off the old one, this is what I found:


Installed the new one, fired up the car and climbed underneath. I could still feel the exhaust leaking out on the top/bottom (basically 90* from where the 2 bolts are) still!

How does one go about fixing this? The two flanges look flat to me and mate flushly.

Try to use the Thick Gasket maker, It works Better than that because you can make it a little bit bigger, Tighten the crap out of it and it will seal before it ever leaks.

YOU have to make shure it is extremly tight, I find this 2 bolt design bad because as it shows the gasket begins to leak as you show, Use the good thick gasket maker never had a problem with it before.

Also that looks like a horrible gasket in the first place it is extremly uneven.

The new gasket I got is considerably thicker than the one I pealed off -- yet it still leaks. Bad idea to slap two gaskets together?

Yeah you could put two gaskets together

always use some kind of heat resistant silicone (gasket maker type stuff) when putting exhaust together. beleive me it will save you alot of hassle, i've done plenty of exhausts and have never had one come back leaking that i used silicone on.
-ALex

the problem is gaskets will compress. Even copper and aluminum. Even if you tq those bolts down like a MOFO, after heat cycles, bolts can loosen because the gasket compresses. You need to get under there and check the bolts for the first couple of weeks after putting new gaskets in.

People with F-bodies complain about this all the time (LT1 section) because they use cheap gaskets. They think the bolts are loosening by themselves and then go out and spend oddles on locking bolts, when all they need to do is remember to retighten bolts..

When I had the resonator installed, the put some high temp silicone stuff around that flange. No more leaks. Yes, could've done it myself, but would've been a waste since they'd have to drop the back half of the exhaust to work on it...