Like the title, my RSMs look brand new and I recently replaced all 4 shocks with new bilsteins OEM replacements. This noise predates the new shocks and really wasn't affected by them.

This noise has been around for a while but I somehow always attributed it to something bouncing around in my trunk, because that’s exactly what it sounded like. Last night, however, I realize it had to be something in the suspension when I would hear the cla-CLUNK every time I hit a relatively large bump. Last night was different then normal because I was driving 4 ppl around LA and never hit a bump very fast. The sound didn’t happen in turns unless I hit a bump.

The first beat of the noise is heard when the rear suspension is loaded heavily (i.e. i hit the bump) and the second, louder clunk when it rebounded from the load. "cla-CLUNK"

Any ideas? I'm hoping its something simple like I need new sway bar endlinks or bushings or something. Since I replaced all 4 shocks between me and a friend, I should be able to handle that.

Statistical info
Miles on car: 91000
328is, third owner.
One rear quarter area crash from first owner.
Other then bilsteins suspension is stock.


Any advice would be great. thanks ahead of time!

a couple of things to check that can sometimes make similar noises as you describe:

1. rear parking brake assembly could be loose inside (you'll have to take off the rear rotors to inspect

2. rear subframe floor pan failure. you'll have to rip out the trunk and look for failed spot welds.

3. jack in your trunk could be loose, re-secure it.

I think some folks on these boards were reporting similiar issues that turned out to be loose differential bolts. Might want to take a look for peace of mind.

diff bolt issues will create noises when shifting.

in addition to what bimmerz5 said, i would check:
-outer ball joints/bushings. this is common. mine started to "clunk" at 73k.
-rear trailing arm bushings. not very common but can create noises.
-struts. blown struts sometimes make awfully loud noises.

gl

My experiences... (1) metal exhaust support just before the cats had a crack and made annoying noises, (2) sheet metal brake shield was a little out of shape so when i hit bumps it would make clunk against something making noises.

BTW I installed Bilsteins w/o replacing the RSM's, due to the vastly increased shock stiffness the RSM's wre torn apart about 6 months after the install. These make a VERY load noise when they fail, like some trapped in your trunk trying to get out.

Check the exhaust hangers...I went through the same thing.