Clunking on bumpy roads at slow speed

[Sixle]

Hi Guys,

Just wanted to reach out for some help and see if anyone had a similar issue to one I'm having currently.

I am running Eibach Multi Pro-R2 Shocks which have been installed since January, the car has not made this noise until two weeks ago.

When I'm driving slowly (10-15mph) over bumpy or uneven surfaces I get a very persistent clunk (not quite a metallic sound) which sounds like its coming from the rear left shock tower. I managed to get the car off the ground on that corner, removed the wheel, and began to vigorously shake the suspension components and couldn't tell of any movement in the strut, control arms, or camber link. I climbed in the trunk and un-tightened and re-tightened the upper shock mount inside of the trunk to no avail. I'm unconvinced the lower shock mount is the source of the noise.

http://www.e90post.com/forums/showthread.php?t=748179

I saw in this thread under post 4 that it's possible that the upper bushing nipple on the wheel well side has come out of the sheet metal which sounds like it may be my problem, however I can't remember from my install if the aftermarket shocks had the same bushing interface that the oem part had.

Anyone else on aftermarket suspension run into this problem?

[andrey_gta]

check sway bar bolts

[Sixle]

Originally Posted by andrey_gta

check sway bar bolts

Checked and they don't seem to be the problem

[Pig Farmer]

Originally Posted by Sixle

Hi Guys,

Just wanted to reach out for some help and see if anyone had a similar issue to one I'm having currently.

I am running Eibach Multi Pro-R2 Shocks which have been installed since January, the car has not made this noise until two weeks ago.

When I'm driving slowly (10-15mph) over bumpy or uneven surfaces I get a very persistent clunk (not quite a metallic sound) which sounds like its coming from the rear left shock tower. I managed to get the car off the ground on that corner, removed the wheel, and began to vigorously shake the suspension components and couldn't tell of any movement in the strut, control arms, or camber link. I climbed in the trunk and un-tightened and re-tightened the upper shock mount inside of the trunk to no avail. I'm unconvinced the lower shock mount is the source of the noise.

http://www.e90post.com/forums/showthread.php?t=748179

I saw in this thread under post 4 that it's possible that the upper bushing nipple on the wheel well side has come out of the sheet metal which sounds like it may be my problem, however I can't remember from my install if the aftermarket shocks had the same bushing interface that the oem part had.

Anyone else on aftermarket suspension run into this problem?

First thing I would do is re-torque the nut on the bottom of the rear shock. If you happened to torque that nut when the car was on a lift or jack stand, I can almost guarantee that's your issue. Torque to 60 Nm (44ft-lb).

[Sixle]

All of the tightening of suspension components has been done with the car on the ground or with the jack preloading the camber link.

[Ski Killset]

Are you tunning the runflat tires?

[Sixle]

Originally Posted by Ski Killset

Are you running the runflat tires?

No, I ditched the stock RFT's for Potenza S04's last July

[Elsabor67]

Try swapping out that shock for the OEM shock if you have it. If the clunking persists, check all the bushings on that side.

I have a feeling that your shock might have gone bad.

[Sixle]

So after getting the rear end apart I managed to hear a much less audible version of the noise which sounded like it was coming from the top mount or from inside the shock.

Fearing a blown damper I pulled out the strut and compressed it a few times listening closely from any odd clicking inside the shock and after a little exploration and moving the flashlight around I noticed the rubber on the inside of the lower rear shock mount seemed a little rough, I pulled off the mount and the rubber fell off exposing the metal sleeve in the rear shock mount. I've order a new one and will report back with the result once the fresh mount is installed

[Sixle]

Originally Posted by Elsabor67

Try swapping out that shock for the OEM shock if you have it. If the clunking persists, check all the bushings on that side.

I have a feeling that your shock might have gone bad.

After installing the new lower shock mount the problem still persists as bad as it was. I called Eibach today and opened up a case number so that I can get an RA and possibly send the shock in.

Before I do send it in, I'm going to completely remove the rear sway bar end-links to see if the noise goes away. I tightened the links and thrashed on the sway-bar a bit without reproducing the noise but removing the links is the only way I'll be positive it isn't those bolts.

[Sixle]

Just wanted to update this with my warranty claim with Eibach. Turns out the damper was in fact leaking internally. When I jacked up the shock to where it would sit with the vehicle weight on it and shook the shock body it would then make the rattle I was hearing but it wouldn't make the noise when it was fully uncompressed.

I asked Abel at Eibach what the results from my shock were and got this:

"Attached are the Dyno test sheets that we did for your damper.

The shock definitely leaked oil which caused the floating piston (oil and gas separator) to move upwards to the compression adjuster. So when that happened and the shock was being cycled as the vehicle was being driven, the compression adjuster and the floating piston were hitting each other (metal to metal). That is where the noise was coming from that you were hearing. All necessary parts were replaced to stop the leaking."


I'm not sure if that was the cause of the clunk because the noise could still be made when the shock wasn't cycling, also the floating piston is inside the reservoir, not the damper body. Regardless, the rebuild process tightened up whatever was loose internally causing the knock.

While the shock was being serviced I installed AKG Motorsport 75D subframe bushings. I'll post a review after i get some time on them

[jyamona]

Originally Posted by Sixle

Just wanted to update this with my warranty claim with Eibach. Turns out the damper was in fact leaking internally. When I jacked up the shock to where it would sit with the vehicle weight on it and shook the shock body it would then make the rattle I was hearing but it wouldn't make the noise when it was fully uncompressed.

I asked Abel at Eibach what the results from my shock were and got this:

"Attached are the Dyno test sheets that we did for your damper.

The shock definitely leaked oil which caused the floating piston (oil and gas separator) to move upwards to the compression adjuster. So when that happened and the shock was being cycled as the vehicle was being driven, the compression adjuster and the floating piston were hitting each other (metal to metal). That is where the noise was coming from that you were hearing. All necessary parts were replaced to stop the leaking."


I'm not sure if that was the cause of the clunk because the noise could still be made when the shock wasn't cycling, also the floating piston is inside the reservoir, not the damper body. Regardless, the rebuild process tightened up whatever was loose internally causing the knock.

While the shock was being serviced I installed AKG Motorsport 75D subframe bushings. I'll post a review after i get some time on them

Verdict on the AKG 75D bushings?

[Sixle]

Originally Posted by jyamona

Verdict on the AKG 75D bushings?

Absolutely in Love.

I built my own tool and had all 4 stock bushings out and all the AKG bushings back in in roughly 1.5 hrs on my garage floor. The car handles much more predictably, as most people said the stiffer bushings make the front and rear suspension play together a lot better.

- No noticable NVH

- No squeaks

One interesting thing I did notice is that when the rear wheels break traction it used to be very noticeable because it felt the the subframe would shock load and bounce around under the car, now under heavy cornering or acceleration if a wheel starts to spin I can barely tell through the chassis of car unless the wheel spin light is flashing. Hoping I can jump into an LSD later this year but I'm extremely pleased with how they turned out.

Most underrated bushings for the 1 as far as I'm concerned, I would buy them over M3 bushings or powerflex anyday the ease of installation is probably the biggest selling point. Didn't have to disconnect brake lines or anything.

[Pig Farmer]

Originally Posted by Sixle

Didn't have to disconnect brake lines or anything.

So the front and rear are pressed in from the bottom? That's great to know if someone out there is planning on a DIY bushing swap.

[Sixle]

Originally Posted by Pig Farmer

So the front and rear are pressed in from the bottom? That's great to know if someone out there is planning on a DIY bushing swap.

Both front and rear bushings are pressed in from both the top and bottom (8 pieces, 4 two-piece sets) but since they're half the thickness and don't need bushing tool to press them into the subframe, it will be low enough to fit the top upper bushing into place without disconnecting the brake lines.

The rear bushings have ample room to work around in.