Whenever I start my car I seem to have this rattle that sounds like a chain being dragged over a table. I thought it was the idler pulley so I replaced that (it was rattling too but it wasn't the true culpret), but I still have a fairly audible rattle. I had thought it was fixed but I pulled through a drive-through recently and I could easily hear the rattle again (the sound was bouncing off the wall). I tried to use one of those automotive stethoscopes but I can't seem to find the problem. When I sit in park I hear it, and when I am driving at low speeds I hear it. When I punch the throttle for about a second I can hear the rattle speed up and then it disappears. I used to get the sound in the fall on a cold day, and it was significantly louder but now I get it almost every start and it stays. If anyone can shed light on the problem I would appreciate it. My car is an auto 91 305 RS if that matters. Thanks in advance.

 

exhaust parts

 

Would the rattling be coming from the cat? I have a new hooker cat-back but this rattle was there before I installed it.

 

Could be.

Have somebody get in the car and work the gas pedal, make the car make the noise while you poke around and listen for where it's coming from.

Not a particularly difficult thing to figure out how to find.

 

I think exhaust too. Could be a hanger came loose and is letting your pipes bang around or the brick in your cat(s) could be shot, having crumbled a bit and it rattling in the case. I think something has simply worked itself loose.

Eric

 

Is it consistent through the RPM range? Are you sure it's coming from the engine bay?

 

Exhaust heat shields, hangers, air tubes etc are notorious for rattling sounds. That being said, I wouldn't think that it would sound like a rattling chain at all. The only problem I've had that sounded like that was a sway bar with no bushings (worn to nothing) and the washers were rattling. I would still start with the exhaust though since the sound may just be a matter of opinion. Listen closely to the car when its making the sound to get an idea of what area it comes from. Then start shaking stuff in that area. You will probably locate the source (don't grab hot exhaust pipes )




Also, it could be the timing chain. Can't rule that one out unless its new.

 

Ha,
I got the same rattle. Kept me awake for weeks.
I just learned to live with it, untill it really shows it self by falling off or braking. Its not that bad once the car warms up, but before that with some accell you can hear it.

rrrrrrrrrrrrrrrrrrrrr, .... rrrrrrrrrrr, ...rrrrr.

Something like that.

 

The sound is present when the car is in park, and in the lower RPM range especially when going slow in a neighborhood or something. I think its from behind the engine bay, because when I open the hood I can't really hear it over the engines noise, but when Im by the sides of the car I can hear it. I also had read that maybe it could be the torque converter bolts coming loose, I probobly need to just jack the car up and see exactly where its coming from since I cant really get under right now with the gfx.