Wipeout

This would be the worst 5th gear rattle I've ever heard in a 944. Torque tube does squeak with clutch out, but the rattle sound is from the muffler area. If I put my head under the car with it on on the left side of the driver's rear tire, I hear the torque tube. If I put it on the right side of the driver's rear tire, I hear the rattle.

knfeparty

It's possible that some of the baffling has broken off and is rattling around in the bottom of the muffler. Best way to get rid of that would be to take it to a track day and blow it out real good.

Does it sound like debris in the muffler or the whole muffler hitting something else?

Wipeout

I'm not sure. I get a rattle at idle and a hell of a lot more on deceleration. It does not sound like the muffler is hitting anything.

Should I drive it like I stole it?

knfeparty

An exhaust rattle won't further damage anything else other than more exhaust work. But if it's something else that you're mistaking for the exhaust well maybe that's not such a great idea. Did you try getting a telltale (piece of paper/string or something) to test for exhaust leaks? Just you know hold it next to the exhaust in places and see if it moves from the leaking exhaust.

Wipeout

I did not, but that is a good idea.

Here's a question...does an early NA exhaust mate up to an S2 from the cat flange back?

Wipeout

Found it. The weld that holds the pipe to the muffler has gone bad. If I wiggle the pipe I can see it move. Now to find a shop that'll tack a bead on there for me...

vro944om

wait, "fifth gear rattle"? wow if i accelerate on my 5th the i cant even see my rear view mirror.

Wipeout

So, here's where the problem was:

OntarioTurbo

Tricky spot to weld. Steel on muffler is thinner than the pipe so you have to concentrate heat on the pipe. Invaribly it will crack again however, as the surrounding metal will weaken as you heat it. Perhaps just brazing it will get you by for a while. You might want to look into a new cat back system.

Wipeout

I had them replace it with the exhaust off my '85 NA. Eventually I'll probably get a new cat back system, but I have other priorities that trump "I want a louder exhaust."