Cass944

i was having a very nast vibration and loud noise at about 4k rpms for a while. i thought it was my motoro mounts so i just replaced both of them. i tookthe car for a test drive. as soon as i started it up i had a VERY nasty exhaust leak that sounded like a freakin lawn mower or something. the vibration seems to have gone awya but now there is a new vibration because of the hole that seems to be somewere near my cat.

is it possible that the vibration was coming from my cat in the first place? do those things get clogged up to were they start making pressure that could blow out one of the welds eventually? that kinda seems to be what happened.

Mike Murcia

Did you notice a loss of power while your engine was vibrating so badly? A cat that would be clogged that badly would definitely rob you of some performance.

Cass944

yeah i had a loss of power for a while

ERAU-944

check the weld on the cat pipe. i had it break off on our 85.5, had it welded on at a muffler shop for $20.

-Mike-

Jamie944

Hey Cass, does your car run with a little more power when cold and then the power starts dropping as it warms up. The particles fall into the cat when cool and give you better air flow. When the car is running they warm up fly around and clog the air flow. The easiest way to check is to have a muffler shop test it. It will only take a few minutes then you will know for sure.

Lousailor

Ditto on the crack, in fact my current cat was fixed once and has since developed another crack in the same area (just forward of the cat, where it's welded to the pipe. Had it welded again, so I hope it holds.

dgz924s

Didn't you just do the belts? Could be balance shaft is off. Dal