Rear suspension knocking noise

summit425 · 06-04-2009, 02:03 AM

Hi guys

I had knocking noise since when I had my OEM suspension on and now I put Eibach Coilover on my car.

I still hear knocking noise and I suspect that my rear shock mounts are gone.

So I ordered a set of Rogue Engineering Rear Shock Mount and installed them.

Seems like knocking noise is reduced a lot but it's still there.

Do you have any idea where is the source of knocking noise?

It's definitely from the rear suspension area.

Also when I put my gear Drive to Reverse then I hear "knock" noise.

I can hear knocking noise especially when I go on the ramp slowly.

This noise is very annoying and if you had this kind of situation before please share with me your experience.

Thanks in advance.

e30bim · 06-04-2009, 09:59 AM

Maybe the springs aren't seated properly.

Ceeker · 06-04-2009, 10:24 AM

Get a buddy a REAL GOOD buddy of yours and throw him in the trunk and drive around for a while. Since he's inside he'll be able to narrow down where the noise is coming from.

damameke · 06-04-2009, 12:43 PM

You had your RSM and coilover done by Bimmersport, was it riding quiet after the install?

I would check the sway bar, is it tightened.?

I would definitely ask Bimmerpsort to check it out, since the noise is bothering you.

summit425 · 06-04-2009, 09:23 PM

oh guys... now the knocking noise is almost same as before I change my RSM, meaning that RSM wasn't the problem. I had this kind of noise before I install my coilover...

What could it be?? I already asked my friend to see where the noise is coming from and he and I both agreed that the noise is from the shock mount area. that's what made me to get a set of Rogue's RSM.

It's getting worse and worse, I mean the first day installed, seems like the noise is gone. Next day some came back, now it's like no difference compare to prior installation of RSM.

Could it be the sway bar?? I mean I just hate the fact that I might have to pay another labour regardless which shop I take..

Steve@ASPTuning · 06-07-2009, 07:01 PM

Subframe? issue...If so, BMW should cover it... In fact they are OBLIGATED to cover it since there's a HUGE lawsuit in USA about this. SO BMW Canada should cover it since they've elected to cover a few E46's from what I've read on Canadians forums.

The verdict is still to be announce on August 3, 2009.

Steve
ASPTuning

Swerve · 06-08-2009, 11:15 PM

my knocking noise came from 3 different places in the rear!
RSMs: got Rogue Engineering mounts.
Swaybar end links: got new ones.
non M exhaust rubber hangers tore because M3 exhaust is heavier than non-M. My exhaust was hitting my swaybar! Replaced with M3 exhaust hangers.
If you need the hangers, I have a new spare set from bimmerspecialist. I ended up inadvertently getting a second set with some brackets, so have the ones from bimmerspecialist left over.

330DTM · 06-09-2009, 12:41 AM

Hm, check to see if the rear shocks & RSM's are bolted tightly?

When I installed my C/O and Rogue RSM's, I remember hearing a metal bumping metal sound whenever I went over bumps. Turns out I didn't tighten the rear shocks properly.

By the way, what sway-bar are you running? If you're running UUC I think there might be a chance that it could be rubbing the drive shaft from what I've read around on the forums, so you might need to have it re-aligned.

On another note, I saw you on the road this past weekend. You were on Leslie traveling south of York Mills. I very briefly caught up behind you but I had to make a turn into a residential area. Nice ride!

summit425 · 06-09-2009, 01:50 AM

Quote:

Originally Posted by 330DTM

Hm, check to see if the rear shocks & RSM's are bolted tightly?

When I installed my C/O and Rogue RSM's, I remember hearing a metal bumping metal sound whenever I went over bumps. Turns out I didn't tighten the rear shocks properly.

By the way, what sway-bar are you running? If you're running UUC I think there might be a chance that it could be rubbing the drive shaft from what I've read around on the forums, so you might need to have it re-aligned.

On another note, I saw you on the road this past weekend. You were on Leslie traveling south of York Mills. I very briefly caught up behind you but I had to make a turn into a residential area. Nice ride!

Thanks everyone for inputs.

I will check my sub-frame. Currently I am running OEM sway bar but everything seems fine...

haha yeah I think it was on friday right? I went to see a service manager @ Parkview BMW.

BiBimBap · 06-18-2009, 09:11 PM

Check your RTABs- Rear Trailing Arm Bushings... I had the exact same problem a while ago and that clunking drove me nuts.

328is · 06-19-2009, 07:05 AM

X2 for the RTAB, i had the same thing and changing them solved the problem.

topaz330ci · 06-19-2009, 09:42 AM

i have a weird noise like that also, and my mechanic checked everything and said there is nothing wrong lol, i'm leaning towards the rear left speaker now!

Porter86 · 06-21-2009, 04:54 AM

I had what sounds to be the same prob, and than it got REALLLL bad on ds, so had it all looked at by the guys AE and it was rear shocks, the d/s rear was cracked, and RTAB where FUBAR!! i still have the same noise when going over bumps, so whats this subframe issue? lol

noodles101 · 06-22-2009, 07:21 PM

trailing arm bushing.

WASABI · 06-24-2009, 11:44 PM

I had this "thump" too, replaced my RTABs, and it was still there. Turned out to be a loose spare tire in the trunk.