Feels like: Rear end falling off! Z4 Coupe / FIXED!

[kartman]

I got this noise coming from the rear of my car, a 2007 Z4 3.0si automatic.

If you ever owned a coupe, you will know that when driving with nothing in trunk, you hear /feel fairly well whats happening on the rear axle.

Imagine a big wrench being flopped around in trunk on the trunk lining. Thats the sound. It happens on bumps.

Subframe failure?
Springs failure?
Other suspension issues with control arms or whatnot? Thats what mechanic thinks as he found play in one wheel. :headbang:

Here is whats puzzling: Noise came after rear brake pad change. I had the car serviced by my usual mechanic who did scheduled maintenance.

Once I heard the noise we took a drive, noticed the noise and put it back on the lift. He saw subframe cracks and broken springs on E46 in past and checked all that. Everything was in top shape. Nothing wrong.

So Im going back for more thorough overview today but if anyone had experience with this please let me know! Naturally terrified something is massively wrong with the car.

 

[AlanJ]

Had you not had it checked I would have gone for a broken rear spring with the broken section using the noise as it moves in the base of the spring mount over bumps.
Thorough check may reveal and hope its something simple and not expensive.

 

[hopz121]

Sounds like RTAB are shot if you ask me or a spring has snapped or the rear shock top mounts are gone.

 

[kartman]

Sounds like RTAB are shot if you ask me or a spring has snapped or the rear shock top mounts are gone.

He thought RTAB too. Parts not in yet, will know tomorrow... goddamn. RSMs would be a lot more annoying, gonna hate to see geometry messed up and all. But lets hope i get to the bottom of this soon. Frame looks OK btw. Springs are OK.

 

[hopz121]

Sounds like RTAB are shot if you ask me or a spring has snapped or the rear shock top mounts are gone.

He thought RTAB too. Parts not in yet, will know tomorrow... goddamn.

Keep us upto date, i have fitted Powerflex RTAB to mine and it made a huge difference

 

[kartman]

Sounds like RTAB are shot if you ask me or a spring has snapped or the rear shock top mounts are gone.

He thought RTAB too. Parts not in yet, will know tomorrow... goddamn.

Keep us upto date, i have fitted Powerflex RTAB to mine and it made a huge difference

Why are they superior to OEMs? Does it drive better too?

 

[hopz121]

Alot better, it stiffens up the rear end a treat and doesn't allow much side to side movement like OEM does.

 

[kartman]

Alot better, it stiffens up the rear end a treat and doesn't allow much side to side movement like OEM does.

BTW, the geometry so far of the rear axles looks fine, i.e. visually rims all sit correctly etc. Wheels also were not "moving" in any direction when on a lift / so hopefully RSMs are ok. There was some noise in the number 6 in diagram as he showed me. But I could be wrong, going from memory and not a mechanic.

http://realoem.com/bmw/showparts.do?model=DU51&mospid=49421&btnr=33_1141&hg=33&fg=45

 

[simonlpearce]

If it only happened since the pads were changed, is it possible they are not seated properly, and did they put any copper slip on to stop them being noisy?

 

[kartman]

If it only happened since the pads were changed, is it possible they are not seated properly, and did they put any copper slip on to stop them being noisy?

no, the noise is of a different nature to what what happen in case of a problem you described.

 

[hopz121]

What pads did you use out of interest?

I know Red stuff rear pads have a habbit of not fitting correctly and they rattle, might be worth a look

 

[Taz]

if it was just a rattle i would check the exhaust, Spikey showed me a split in is exhaust mounting which causes a rattle

 

[jan_tekin]

if it was just a rattle i would check the exhaust, Spiley showed me a split in is exhaust mouting which causes a rattle

x2 The hangers have a habit of breaking

 

[kartman]

SO. An update.

The rear drop link was indeed the issue. Helluva noise, but once replaced / all super smooth and quiet. He checked the car, said all is fine and that was it. The cost was a joke / 25 EUR. Happy camper.

Now for summer tyre change, then alignment, and then a full polish/wax.


EDIT>

I assume that the rear drop link

thx mate!

 

[jan_tekin]

I assume that the rear drop link

 

[kartman]

I assume that the rear drop link

:rofl:

EXACTLY! So for all who have a nasty loud banging sound in back / check that bit!

 

[Taz]

glad its sorted and not expensive

 

[mad4slalom]

SO. An update.

The rear drop link was indeed the issue. Helluva noise, but once replaced / all super smooth and quiet. He checked the car, said all is fine and that was it. The cost was a joke / 25 EUR. Happy camper.

Now for summer tyre change, then alignment, and then a full polish/wax.


EDIT>

I assume that the rear drop link

thx mate!

how much do the polish guys charge for a full wax where you live ? :tumbleweed:

 

[kartman]

SO. An update.

The rear drop link was indeed the issue. Helluva noise, but once replaced / all super smooth and quiet. He checked the car, said all is fine and that was it. The cost was a joke / 25 EUR. Happy camper.

Now for summer tyre change, then alignment, and then a full polish/wax.


EDIT>

I assume that the rear drop link

thx mate!

how much do the polish guys charge for a full wax where you live ? :tumbleweed:

I dont know, how much would you charge me?

I have my friend who is a mechanic. I pretty much pay cost on parts and job was fast. I have no idea what dealer would charge me but probably about 60-70 EUR. You probably would pay 50 GBP I would guess.