Significant rattle
Thread Starter
Racer
Joined: Mar 2015
Posts: 415
Likes: 284
From: Indianapolis
Significant rattle
(Finally) took the C5 for a test run today before getting her registered for the summer.
Noticed a very significant rattle (Sounds like a handful of bolts in a coffee can) coming from the tunnel and/or clutch area. Was able to hear it a bit at idle, but noise is very prominent at 2k RPMs. Doesn't matter if clutch is engaged or not, car is moving or not. It is 100% RPM based. The noise seemed to get worse after I did a quick 0-60 pull getting onto the highway (got up to about 5k RPM).
I'm hoping that it's either the exhaust hitting the body again (picking up some Longtubes on Sunday) or the cat material has broken loose and is rattling around. My plan was to get it in the air and start tapping with a rubber mallet, and if that didn't work drop the mid-pipe and tunnel plate and start inspecting the TT, clutch, etc. But, before I start investigating, I wanted to ask the more knowledgeable if there is anything else I should check? Any common issues I should know about? Also, is there any chance this sounds like the Pilot Bearing?
Noticed a very significant rattle (Sounds like a handful of bolts in a coffee can) coming from the tunnel and/or clutch area. Was able to hear it a bit at idle, but noise is very prominent at 2k RPMs. Doesn't matter if clutch is engaged or not, car is moving or not. It is 100% RPM based. The noise seemed to get worse after I did a quick 0-60 pull getting onto the highway (got up to about 5k RPM).
I'm hoping that it's either the exhaust hitting the body again (picking up some Longtubes on Sunday) or the cat material has broken loose and is rattling around. My plan was to get it in the air and start tapping with a rubber mallet, and if that didn't work drop the mid-pipe and tunnel plate and start inspecting the TT, clutch, etc. But, before I start investigating, I wanted to ask the more knowledgeable if there is anything else I should check? Any common issues I should know about? Also, is there any chance this sounds like the Pilot Bearing?
Melting Slicks
Joined: Dec 2018
Posts: 2,677
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From: Orange County, CA
If you have a way to safely get the car up in the air while it's running, have someone give it some throttle (maybe even in gear) and see if you can locate it. Might require using high-temperature-safe gloves while you use your hand(s) to apply force to things like the exhaust system.
In my experience this does sound like exhaust contact. The "dead giveaway" IMO is that the rattle increased after a pull when the exhaust pipes would've grown from increased exhaust temperature.
In my experience this does sound like exhaust contact. The "dead giveaway" IMO is that the rattle increased after a pull when the exhaust pipes would've grown from increased exhaust temperature.
Thread Starter
Racer
Joined: Mar 2015
Posts: 415
Likes: 284
From: Indianapolis
So after I got it cooled down (quickly thanks to a couple of box fans) I jacked it up and started tapping with a mallet. Im about 95% certain it's the catalytic converter material. I attached a video of me tapping on it.
All of the bolts are tight, and the tunnel plate sounds solid as a rock. Based on the noise I don't think it's the PB or clutch related.
If I weren't buying LTs in a few days id pull the exhaust down and gut the cats but doesn't feel like it's worth it now.
All of the bolts are tight, and the tunnel plate sounds solid as a rock. Based on the noise I don't think it's the PB or clutch related.
If I weren't buying LTs in a few days id pull the exhaust down and gut the cats but doesn't feel like it's worth it now.
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Good luck - hope you are right that it is a bad catalytic converter.
Thread Starter
Racer
Joined: Mar 2015
Posts: 415
Likes: 284
From: Indianapolis
So Im fully convinced its the cat material. Did another WOT pull to about 5500rpm and the rattle has been gone since. My assumption is that I blew out whatever material was left.
Got a set of headers from a forum member, just need to get an X-pipe kit and I can them installed (as well as the hooker axle back ive had sitting on a shelf for almost 3 years!)
Got a set of headers from a forum member, just need to get an X-pipe kit and I can them installed (as well as the hooker axle back ive had sitting on a shelf for almost 3 years!)
