Exhaust Leak

[legion]

When I pulled of the rear pan under the engine (to get to the power steering line--see the "Leaks" thread), I noticed black soot on the pan corresponding to the right rear corner of the oil pan--tell tale sign of an exhaust leak.

Problem is, I can't figure out what is actually leaking. It has to be either the crossover pipe or the junction between the crossover pipe and the headers. I can't see any evidence of an actual exhaust leak on the pipes themselves. Anyone know any tricks?

[Razorback1980]

Mix a little oil and gas together and squirt in the intake and look for where the smoke is coming from.

[legion]

Can I get the crossover pipe welded or should I just get a new one?

Can it be welded on the car or should I take it off?

[Steve Schubert]

I have a 85/2 NA and today I went to Midas and got the pipe welded just brfore the cat converter. They said the exhaust was S.S. Car sounds like new. I'd try finding the leak and welding on the car first.

Where my pipe broke is easier to get to they your leak. $60 to fix.

[Razorback1980]

The decision maker is where the pipe is broken. Typically with Stainless steel headers they break in the joint on the header between 1 and 4. With mine, I had to take it off and remove the gussett, weld the headers and weld the gussett back on. I've been told that once you do that, then they will be fine from then on...with mine...so far so good. There would have been no way to weld mine on the car. Sounds like Steve's broke in a different place.

[Panzer909]

Just curious - do exhaust leaks like that typically effect thr running or performance in any way?

[legion]

When they are between the headers and turbocharger they do!!!

[Razorback1980]

Exhaust leaks do affect the performance in a couple of ways. First, as Legion already mentioned, it won't spin up the turbo charger as much as it could. Second, the O2 sensor won't get accurate readings because some of the exhaust gases have escaped...and last, the exhaust valves get very hot while running and I've been told that if they cool down too fast, they will warp and start to leak. Of course the other problem with an exhaust leak especially in the front of the car is you don't really want that carbon monoxide going into the cabin of your car.

[david c.]

I just bought my 89 and I can hear a leak under the car somewhere. I'm not familiar with this car but I can say that the shifter area gets HOT when driving around. I don't smell exhaust in the car, but the shifter certainly is getting warm from a leak somewhere down there.

[legion]

Sounds like you have a leak between the cat and muffler. Check the three-bolt flange and insure the sealing ring is intact.

[david c.]

Roger. Thanks!

[legion]

Mind you, the flanges themselves could be rusting off, but I always start with the cheapest thing first...