: Corsa Making a Racket in Heavy Rain



MLV
06-16-05, 09:45 PM
A while back someone mentioned that their Corsa exhaust was making a lot of noise (clanging, banging, etc.) when driving in rain. Mine recently started doing the same thing. Once it starts, it sounds like the thing is coming apart and doesn't stop until I pull over and stop; then it's okay again for a while. Any ideas on what causes this. My pipes are welded, so it's not because they have come loose. Thanks. :annoyed:

DILLIGAF
06-16-05, 09:51 PM
Somethings loose,re-check.Mine came loose,re-tightened bolts=fine

6104696
06-17-05, 06:08 AM
Maybe one of your flange bolts broke? I hope that wasn't welded! Otr could one of your hangers slipped off or broke?

Or....is there enough play if the cradle is loose for the cradle to have shifted and reduce the clearance between the sway bar and the muffler inlet tube? It would make sense for it to go away when warm since the system expands about 1/2 inch in length at operating temp.

Doug

c5racr1
06-17-05, 08:19 AM
mine did the same thing one of teh flange bolts either got lose during the rain or the pipe just slipped , it turned an struck the weight on the drive shaft. check it out to see if it slipped. the damdest sound you ever heard!

trukk
06-17-05, 08:41 AM
That was me:

http://www.cadillacforums.com/forums/showthread.php?t=35845

For me it was DEFINATELY the exhaust smacking the drive shaft, just aft of the resonator. Specifically, there is a Driveshaft balancing weight there, that sticks out perhaps 1/8 of an inch, and it was mashing the hell outta my exhaust (scaped it up a bit, but no real damage).

I loosened everything up, and then re tightened it, and it has helped a bit (done this twice). I've had it happen two other times since then. I think what I really need to do, is take the whole thing off, and tighten up the connection between the resonator, and the aft pipes, and make sure they are perfectly even, length wise. Currently I have one pipe that is perhaps 1/8 - 3/16 inch longer than the other, and it makes the resonator section hang just a bit lower on the drivers side (the passenger side pipe is longer).

Since your's is welded, you may want to check, that the resonator is hanging perfectly level, and of course check the flange between the cats, and the front of the Corsa. In the end you may want to mod the ruber hangers at the rear, to sit a 1/4" or so lower, to give you just a bit more clearance up front.

I think the overall issue with this, and why we see it in heavy rain, is that the exhaust gets really hot, and expands. When you get a bunch of water splashed on it in a hurry, it very quickly contracts, which causes the DS to contact the exhaust. What I've done in the past, is pull over, and rev the engine for a few minutes, to bring it back up to temp, and expand it again. Unless you hit another large puddle (or it is raining HELLA hard), you shouldn't have another problem.

I wonder if anyone else is having this problem? I wouldn't expect that Corsa has sold more than a few hundred of these (due to the small production numbers of our car), and a lot of those don't see the road in heavy rain.

Install specific issue or systemic? Time will tell.

I'd love to here if anyone else has had this problem.

-Chris

trukk
06-17-05, 08:42 AM
BTW, the last time I had this happen, I had just tightened everything up, and corrected the pipe length issue (with a big rubber mallet), the day before.

-Chris

MLV
06-17-05, 08:56 PM
Thanks, guys; I'll let you know what I find out. I think Trukk may be right since I had a problem with the drive shaft striking the pipes when the exhaust was initially installed. It's been several months and it seemed to be fixed, but I guess something has shifted.