Rear suspension clunk?

mmret · 05-23-2011, 11:36 AM

Have a 2007 E85 Z4 3.0si Roadster....totally stock except for aftermarket 18" wheels (proper offset and tire size, nothing bonkers here).

Going around corners and on speed bumps and stuff I always get a clunk from the rear suspension. At first I thought it was stuff in the trunk, but I removed everything and tested it again and the noise is still there.

Pretty new to BMWs but I know early E46s / E46M3s had a problem where the rear subframe would crack over time. Since the Z4 is mechanically similar does it suffer from the same problem?

The car is still warrantied for a little while but it is am import from the US to Canada, hopefully things are still good as far as coverage goes. Getting a mid-cycle oil change next week so will probably ask my indie to take a look at it.

Any ideas?

thekurgan · 05-23-2011, 12:08 PM

You could check your rear sway bar attachment points, they are known to come loose and cause a sound like you describe. If they check out, the rear shock mount can also be an issue, but the sway bars are an easy check.

mmret · 05-23-2011, 12:55 PM

So relatively unlikely to be a subframe cracking problem?

thekurgan · 05-23-2011, 01:05 PM

Quote:

Originally Posted by mmret

So relatively unlikely to be a subframe cracking problem?

I believe the subframe issue was limited to the Z3 platform; I haven't heard of that on an E85/86 platform.

DerekSelmanRacing · 05-23-2011, 01:19 PM

Obviously, it COULD be a lot of things; in my case similar sound was a diff mounting bushing. E85's are not known for weak rear unibody.

mmret · 06-23-2011, 07:28 PM

Quote:

Originally Posted by DerekSelmanRacing

Obviously, it COULD be a lot of things; in my case similar sound was a diff mounting bushing. E85's are not known for weak rear unibody.

Took it to an indie and turns out its the "rear differential bracket" which apparently is cracking at the bolt point. I haven't had a chance to look at it myself and thus haven't been able to figure out exactly which part it is...

Hopefully this will be covered under warranty.

mmret · 03-18-2012, 05:00 PM

Thread necro. Took it to the dealer and they agreed something was up. Apparently they just tightened everything and lubricated stuff and it did go away for a while....but now its back. They said they couldn't see anything cracked or broken.

Car is now out of warranty so I need to find some kind of solution...don't really feel good about taking the car to the track with this odd noise.

Any other ideas at what it could be? I need to find a better indie I guess.

thekurgan · 03-18-2012, 08:52 PM

Did they check the rear shock mounts? This *used* to be an issue on the E46 as shocks aged, but I've not taken apart anything like this on the e85/86.

05-23-2011, 11:36 AM	#1
mmret New Member 0 Rep 14 Posts Drives: 07 Z4 3.0si Join Date: Sep 2010 Location: Toronto iTrader: (0)	Rear suspension clunk? Have a 2007 E85 Z4 3.0si Roadster....totally stock except for aftermarket 18" wheels (proper offset and tire size, nothing bonkers here). Going around corners and on speed bumps and stuff I always get a clunk from the rear suspension. At first I thought it was stuff in the trunk, but I removed everything and tested it again and the noise is still there. Pretty new to BMWs but I know early E46s / E46M3s had a problem where the rear subframe would crack over time. Since the Z4 is mechanically similar does it suffer from the same problem? The car is still warrantied for a little while but it is am import from the US to Canada, hopefully things are still good as far as coverage goes. Getting a mid-cycle oil change next week so will probably ask my indie to take a look at it. Any ideas?
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05-23-2011, 12:08 PM	#2
thekurgan Bad Lieutenant 232 Rep 3,517 Posts Drives: E90M3 Join Date: Aug 2007 Location: Sacramento iTrader: (0) Garage List 2008 BMW M3 [0.00]	You could check your rear sway bar attachment points, they are known to come loose and cause a sound like you describe. If they check out, the rear shock mount can also be an issue, but the sway bars are an easy check. __________________ 02 E39M5 \| TiAg/Schwartz \| Tubi Rumore \| Ultimate Ti Pedals \| E60 SSK \| Jim Blanton 3.45 40/100% \| Coby Alcantara \| StrongStrut STB
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05-23-2011, 12:55 PM	#3
mmret New Member 0 Rep 14 Posts Drives: 07 Z4 3.0si Join Date: Sep 2010 Location: Toronto iTrader: (0)	So relatively unlikely to be a subframe cracking problem?
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05-23-2011, 01:19 PM	#5
DerekSelmanRacing Second Lieutenant 8 Rep 222 Posts Drives: 05 Z4 3.0 SMG, 01 530 Join Date: Jul 2008 Location: Lake Havasu City, AZ. iTrader: (0)	Obviously, it COULD be a lot of things; in my case similar sound was a diff mounting bushing. E85's are not known for weak rear unibody.
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03-18-2012, 05:00 PM	#7
mmret New Member 0 Rep 14 Posts Drives: 07 Z4 3.0si Join Date: Sep 2010 Location: Toronto iTrader: (0)	Thread necro. Took it to the dealer and they agreed something was up. Apparently they just tightened everything and lubricated stuff and it did go away for a while....but now its back. They said they couldn't see anything cracked or broken. Car is now out of warranty so I need to find some kind of solution...don't really feel good about taking the car to the track with this odd noise. Any other ideas at what it could be? I need to find a better indie I guess.
	Appreciate 0 Quote

03-18-2012, 08:52 PM	#8
thekurgan Bad Lieutenant 232 Rep 3,517 Posts Drives: E90M3 Join Date: Aug 2007 Location: Sacramento iTrader: (0) Garage List 2008 BMW M3 [0.00]	Did they check the rear shock mounts? This used to be an issue on the E46 as shocks aged, but I've not taken apart anything like this on the e85/86. __________________ 02 E39M5 \| TiAg/Schwartz \| Tubi Rumore \| Ultimate Ti Pedals \| E60 SSK \| Jim Blanton 3.45 40/100% \| Coby Alcantara \| StrongStrut STB
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