So I was driving last week and managed to hit a pretty nasty bump. After that, I hear a sound similar to something rattling around in the back of the car. It only happens when the left rear side of the car goes over the smallest bump. I have NM lowering springs installed and recently had the car aligned to stock spec.

Does any of this sound familiar?

 

Does it seem to come from about the window line? A rattle, not a clunk?
I have something, Does not seem to be the sunroof ( known). Not the hatch, seat-belt buckles, tools, or shelf. Dealer has not found it. I am thinking something inside the hatch or inside the rear quarters.

 

I had to have the passenger side rear strut replaced due to a rattling sound when going over bumps. (It sounded like maybe the rear doors weren't properly closed; but the sound was coming from the suspension.) Took the dealership quite a while to pinpoint the offending part, but it's all good now.

HOWEVER, this was on a stock suspension, 2010 Clubman. Given your modifications, I'd have to say that it is possible that you have damaged a strut, but it also could be any number of other things instead.

In my case, a passenger riding in the rear held his ear up to various areas until we clearly identified the rattle as coming from right above where the rear wheel is. Maybe trying to same experiment with a passenger will help you pinpoint the location.

--
Darryl

 

It might be your suspension... how hard do you drive the car? Any mods? Big pot holes?

I did something similar... I had someone drive the car around while I sat in the back seat listening. It's definitely a strut... I've already ordered some Koni Sports for the rear and I'll be keeping the NM springs since I really like the way they ride. I've been having some trouble with the rear wheels for a good while now, but it seems that after 14k miles of aggressive driving, I managed to kill a stock strut and damage another one.

 

Maryland roads. Need I say more. I had the rattle before I put the Bilsteins in. The dealer adjusted the hatch. No change.

 

Odd... maybe that wire harness on the left side of the boot is loose? Do you have the comfort access system? If so, check to make sure your antennas are still all properly mounted. If you have a sway bar, I'd also suggest lubricating it and making sure the bolts holding it down are still properly attached. And finally, try getting under the car and making sure the struts are torqued to spec (42 ft. lbs).

 

Not the extra plug on the passenger side behind the access panel. Good guess as that is the kind of thing it sounds like. Something like a nylon plug or metal rod rattling really close to something hard and resonant. I will ask the dealer to check the torque of all the chassis bolts next week when I get my 15K checkup. I found several loose when I did the shocks. ( I also had loose lug bolts). It sounds like it could be inside the hatch. Hard to tell from the front. If they can't find it, I guess it is an excuse to pull all the panels out and put in new 5 x 9's! The rattle is several impacts for over half a second. Not a clunk kind of sound I expect from suspensions. I've been fooled before.

 

It might be one of the panels next to the rear windows... also, it might be that a clip from one of those panels fell and is vibrating between the wall of the car and the plastic cover... You never know.

I found out what my problem is... My struts aren't torqued well enough to the trailing arm because it's stripped... Turns out that if you don't torque them well, they make noise every time you go over a bump.

 

I may have more than one. With the hatch open, it is less, so that does suggest the hatch latch is part of it.

 

Have you checked to see if your glass is rattling? Worst case scenario I would suggest installing sound-deadening mat (fat mat, dynamat, etc).

 

Just reporting in. Koni struts with NM springs are now properly installed on the car... That took care of most of the noise, but there was still a bit of rattle when going over a bump. I checked the sway bar and it wasn't torqued well enough. After fixing that, the car is perfect!

 

lol check the driver and passenger windows when their up and doors are open. i just narrowed my rattle to a passenger window being loose after a bump