Rear End Rattle

[GTP2003GP3]

I recently purchased a 2003 Grand Prix GTP. Just two weeks after driving the car, I started hearing this annoying rattle from the rear as well. I have replaced ALL of the rear suspension (my self), including the strut mounts etc.... and ITS STILL THERE!! I could have swore that it was a strut mount! Ive checked everything on the under body and everything is solid. I have also gone through the rear deck and speakers, as well as, the rear spoiler and trunk lid (everything accounted for and everything tight). STILL THERE! But if I come across something, I will be sure to post here. I am open to ANYTHING and would greatly appreciate any ideas...Thanks

[Teancum]

Same here on my 03 GT. I've gone nuts trying to find it. It sounds like it's almost coming from inside the trunk, but emptying it doesn't change it either. It happens at lower speeds over bumps and then there's a constant rattle at speeds above 70.

[Teancum]

I think I found the solution in another topic. Someone said to push the rear of the car side to side and see if it rattles. It took some hard pushes but it definitely made the same popping sound. They said if that's the case to get the trailing arms looked at - could be a loose adjusting bolt or anything with those arms. I'm taking it to my mechanic today as I don't have time to do suspension stuff.

[GTP2003GP3]

I am also taking mine in today for diagnosis. I will post when I get back. Thanks for the replies.

[Teancum]

Mine ended up being the track bar.The adjustable nut's threads just gave out and it popped apart today. Now I have to limp it to the shop tomorrow - I don't have big enough tools to do it, let alone laying down under jack stands.

[GTP2003GP3]

I took mine in last week, and that is what they told me. He said, "replace your trailing arm bushings". And I did last weekend but... The rattle is still there. Oh well, I have an appointment to get my valve cover gaskets done and ill have him go through the whole rear end, hopefully he'll be able to find something. App isn't till Wednesday but ill do my best to post when I get back.

[Teancum]

This is what was bad on mine - the track bar. It goes from the wheel to the center of the car. What happened is the left side of that large middle bolt (silver in color) had the threads completely ruined. The only thing that was keeping it in was the weight of the car. So when I reversed out of my driveway just right it was enough to separate the two pieces (which weren't threaded together anymore). That's also what caused the rattle as it was the left piece banging in and out of the large center bolt. I'd have them check that thoroughly as I could only do about 20 miles an hour after it finally separated. That was a long drive to the shop.