I recently bought a used 1997 A4. It seems to be running great, but when I go over bumps or uneven pavement I hear an annoying rattling sound from the rear on the driver's side. It seems to be coming from either the door or more likely from where the top of the seatbelt goes into the seat.

I've googled this problem and tried many different things to no avail: putting the seat down, fastening the seat belt even when no one's sitting there, putting tape in the area where the seatbelt goes into the seat. Nothing works and I can't find any loose fittings that could be causing the rattling.

I'm concerned that it must be something either within the door, below the seat, or under the plastic covers near the seatbelt. My next step is going to be taking apart stuff, but I don't know where to start. Does anyone have any idea what I can do to fix this? Other than this problem, the car runs fine, but this rattling noise is REALLY annoying.

 

It is almost impossible to diagnose rattles over the internet.

Drive around with someone in the back seat with one of the seats to the trunk open and see if he can pinpoint the source.

I'll give a couple of guesses.

1. Pull the rear seat bottoms out and look for loose change. Send me 50% of what you find

2. Check the trunk. Under the driver's side rear speaker is a metal bracket that holds the amplifier for the rear speakers. If this gets slammed by luggage, it snaps off and will dangle by the wires and clunk around when you go over bumps.

3. Open the cover in the trunk on the driver's side that hides the CD changer. The wires for the changer are taped to the body of the car (you have to reach forward). If the wires are dangling they can clunk around.

4. Check the spare tire well for junk, etc.

Good luck

 

Thanks. I'll try what you suggested when I get home from work.

I also read in another thread that its common for the rear Bose speakers to rattle because they have some faulty plastic part. They said it's possible to remove the speaker and fix it. I may have to do that, but yeah, I'm first going to drive around a bit more to try to isolate where the sound is coming from. Last time I checked it sounded almost like it was coming from the speaker area so it actually makes sense that it might be the speaker.