I drive a 99 Chevy cavalier and it sounds like there’s bodies rolling around in the back trunk! I don’t know what it could possibly be! And after charging me 85$ for an exhaust hanger i’m tired of being taken advantage of and the noise is still there!
Does the thump increase/decrease with the speed of the car? If so it could be a bad rear tire.
that seems like such a simple answer… it goes away as I drive faster… they’ve told me everything from bad struts to needing a new exhaust hanger!
Bad With Cars, When Driving Straight Ahead At Parking Lot Speed Or Slower In A Parking Lot, Does The Car Seem To Wiggle Slightly From Side-To-Side ?
Also, have you checked the trunk for bodies or bowling balls ? How about any very bad odors, especially on warm days ?
CSA
First thing to do is take everything out of the trunk and see if the noise goes away. If it doesn’t, lift up the carpet in the trunk and take the spare tire and any stuff floating around in the spare tire well. Noise still there? Try pushing the rear and front of the car up and down vigorously. See if you can reproduce the noise. If you can, it probably won’t be too hard to track down.
No luck? Use the jack to raise each wheel one by one. Shake each wheel vigorously – in and out, back and forth, top and bottom. Keep all parts of your anatomy clear of the car at all times. The car may fall off the jack. Won’t harm the car (probably). The same is not true of you. Maybe you can reproduce the noise. Or maybe you will find a wheel that behaves differently than its mate on the other side.
If you can’t reproduce the noise that way, you may have to find a good mechanic and let yourself by taken advantage of.