Rattle/thumping in rear?

I have a thumping sound in the rear of my 99 Grand Prix GT. About 6 months ago a mechanic told me it was my struts. I hade both rear struts replaced. This didn't solve the problem and he thought it may have been in an accident and there is a loose weld somewhere causing the noise.

I have had the car for 3 years now. Does anyone have any idea what else it may be? It is worse when I am driving on a bumppy road. Almost as if there is something bouncing around in the trunk. If I hit a pot hole of go over a speed bump things a fine.(no extra loud bang, what you would expect) It is only when I'm on a bumppy surface. (snow or graval coverd road) Please help it is driving me crazzy!

I have the exact same problem except I'm sure what's causing mine. I backed into something and it only affected my right tail exhaust. It's bent up an inch or two compared to the left, and the body will "thump" against it on uneven roads. I'll have to heat it up and bring it down without spliting the steel hopefully.

I too have a tail pipe that is pushed in and inch or so. I was wondering if that may have been the problem. Thanks for the help. Off the the exhaust shop I go!

Thanks!

OK, I will take a dumb look at it. Seems like you checked everything else. Have you had the spare out lately? A friend used my jack when I was gone for the weekend. Wife didn't tell. The rattle drove me nuts, till I tracked it down.
Door thur to trunk closed and locked? Anything in back arm rest? Jimmy Hoffa in the trunk?
I give,

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Not dumb @ all! My thought exactlly! I pulled everything I could out of the trunk! I even drove with the trunk open thinking it may be the door bouncing!

Did you check for a bad tire?
You know if the car was sitting here, it would be easier. Want to drive to Florida?

http://img.photobucket.com/albums/v425/kustomkid54/Christmas2004001.jpg

I had the same problem in my 97 grand prix i had to replace the rear sway bar mounts and it stopped the noise. cost about 100 bucks to have done..

Kelly,
How long ago did you do that? $100.00, that's what they charge to pull it in the door.
Kenston is a nice little town. Went there when I got out of the Army.

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i live in kingston ny not kenston.. LOL but i did that i would say last yr... the place i went just charged me for the parts... since i had them do a bunch of other work to my car and cause they had to order the parts from the dealer and i got annoyed... so they kinda just threw it in for parts..

Sorry, meant Kingston, NY. On the same trip went to Kingston, Canada.
I have a paint shop that has been painting my car for about 5 months. They have had it 18 times. As a matter of fact, the last time was the 23 of this month. Everyone on this site is tired of hearing about it. I know I am.

http://img.photobucket.com/albums/v425/kustomkid54/Christmas2004001.jpg

LOL i am sure people are tired of hearing about it.. as well i am sure u are tired of talking about it.. LOL but we all have our issues i guess

I have a thumping sound in the rear of my 99 Grand Prix GT. About 6 months ago a mechanic told me it was my struts. I hade both rear struts replaced. This didn't solve the problem and he thought it may have been in an accident and there is a loose weld somewhere causing the noise.


I've got the same sort noise coming from the right rear of my car. I'm convinced it's something in the suspension. Let us know if you ever find out what it is. It's pretty irregular on my car for the time being, so I'm just gonna live with it for now.

I've also got a broken clamp on my rear bumper directly behind my left wheel. That sometimes makes noise over bumps as well, but it's more of a "slap" when the bumper hits against the frame. Just some food for thought.

I had a bunch of noise coming from the rear .Couldnt figure it out.
Ended up being the rubbers on the fuel cap door were missing.
2000SE

Take a look at the wheel bearings. If those things are worn they can cause quite some noise, I just replaced mine and it got rid of that noise