Rattle in the middle or rear

[Guerrillakilla13]

I searched the forums but couldn't find what I was looking for. I'm getting a really bad rattle under the car and I have no idea what it might be. It's on and off, but more "on" then off, and its like a teeth chattering sort of pattern. I hear it mostly over bumps or when i'm at a stoplight. It can get pretty bad/loud when i'm stopped, but for the most part it's just an annoying sound coming into the inside. I already looked under there and (1) tightened the passenger side tailpipe and (2) screwed back in a screw that was coming loose where the metal thing is in the very rear of the underside of the car.

It helped a little bit with some chattering, but there's still something down there making noise. What in the world can it be?? What am I missing here? If this helps, it sounds like its coming from either the middle or back of the car. I also have an aftermarket borla catback. Any help is appreciated!

[SMWS6TA]

check where the torque arm connects to the transmission. Sometimes the bolt can back out if the bushing is worn or damage.

[Guerrillakilla13]

I don't like the sound of that. I'm at work now and wont get home til dark so i'll check on that first thing tomorrow and let you know.

[Firebirdjones]

Could be alot of things, like the torque arm that SMW mentioned.

I'd also look over that aftermarket exhaust really close. Anything you can't get a finger between is a potential rattle and things get pretty tight towards the back. These systems move around quite a bit with those long rubber isolators that the factory uses in the rear.

[SMWS6TA]

Does it make more noise on take off or stopping?

Is it present at idle?

Noise varies with speed or turning?

Feel any vibrations through the pedals or the seat?

[Guerrillakilla13]

Theres a sound thats very persistent and doesn't go away, on top of the rattle. It sounds like the same cause but I have no idea. It's more noticeable when the cars in gear and the brakes are engaged, but takeoff is lower. Braking is where it starts to shine. Its definitely coming from something in the rear..

[pajeff02]

Check all the heat shields under the car. Also, the area where the exhaust goes over the rear axle -- it gets pretty tight to the body through there.

[Guerrillakilla13]

I will, Thanks for the tips. These are all pretty common with the cars? Cause the rattling didnt start until recently, and its extremely annoying. I also think it may have something to do with a metal piece in the middle of the underside that looks like it's there just to be under a section of midpipe..

[pajeff02]

Those areas are known issues. Just for giggles, also check inside your hatch area and spare tire well. Noises can sometimes be difficult to pinpoint.

[Guerrillakilla13]

Found out what it was. The stupid exhaust hangar on the drivers side, near the exhaust tip. The bolt towards the front is stripped and loose, and was causing the thing (part holding the rubber grommet thing) to rattle. Fixing that didn't fix all of the noise, but it was a great start

There is something I found down there however that concerned me a little bit. There's supposed to be three bolts in this part....right?

[SMWS6TA]

yes...that's the top portion of the pan hard bar.

Yikes...

[Guerrillakilla13]

shit, you'd be surprised at how many things I've found down there without any bolts. Is this something I should tend to immediately? I'm gonna hit the hardware store and find something to fit in there, any idea of what size bolts I need?

[SMWS6TA]

yeah that helps keep the car square to the axle.

[pajeff02]

Yowza! Time to go over the entire underside of that car.

[Guerrillakilla13]

unbelievable, I have an idea of which shop did that too. But its been years they'll probably tell me to go f myself. Does anyone know what size bolts those are?

Jeff when I find and screw in those bolts i'm gonna inspect the rest of the damn underside of the car. Good thing it started to rattle!

[pajeff02]

They will be metric -- either a 13 or 15 mm head on them, if I recall correctly. Our car is in "winter storage" right now, so not easy to check.

[Firebirdjones]

I figured it would be something simple back there, but missing bolts completely is a new one, lol. I can't even imagine why someone would take those out other than needing to drop the gas tank. Otherwise that's just a brace for the panhard, that's really not in the way of anything and no need to remove it.

I agree with Jeff, time to go through the entire underside of that car and tighten everything, replace what's missing.

[Guerrillakilla13]

Thank you very much for even thinking about checking it for me. Someone said it was 19mm on all three, does that sound about right?

You know what, meineke did my fuel pump replacement a few years back. I bet it was them. Idiots.

[SMWS6TA]

I know they are the same bolts as the ones on the opposite side. Pull one of those and test first before buying.

[Guerrillakilla13]

Excellent suggestion, I'll check. I think Jeff is right they may be 15. I'm at the dealership now I'll see what they say