Z4M Rocks Back and Forth

wyshyvanuk · 03-22-2020, 08:00 PM

My 2008 Z4M rocks back an forth a couple, three, times when slowly driving over sharp speed bumps. Is that an indication that the rear subframe thingies need replacement, or is it simply normal for the suspension. Thanks for any help!!
Ted

W/// · 03-23-2020, 07:35 AM

Quote:

Originally Posted by wyshyvanuk

My 2008 Z4M rocks back an forth a couple, three, times when slowly driving over sharp speed bumps. Is that an indication that the rear subframe thingies need replacement, or is it simply normal for the suspension. Thanks for any help!!
Ted

Blown shocks maybe

wyshyvanuk · 03-23-2020, 09:41 AM

Sorry, was too lazy to note that the shocks (and struts) were recently replaced with Bilstein B6s. Same back and forth (rather than up and down) motion before and after the replacement.

garz747 · 03-23-2020, 10:50 AM

Check for a broken coil spring- not that uncommon.

wdb · 03-23-2020, 08:58 PM

What are the miles on the car?

KevinC · 03-23-2020, 09:22 PM

Quote:

Originally Posted by garz747

Check for a broken coil spring- not that uncommon.

Ah, good point - very common indeed. But if it's always been an Arizona car, far less likely - seems to be a rust/corrosion issue that was causing the spate of busted springs.

Were any of the bushings renewed (or at least checked) when the shocks were done? Mileage?

wyshyvanuk · 03-24-2020, 05:28 PM

Mileage = 45,000. Didn't check the bushings. Other than the rocking over speed bumps, the suspension seems solid. Thanks!!

KevinC · 03-25-2020, 12:59 PM

Who is your mechanic? I use European Auto Tech in Tucson, they've been great. The main BMW dude is VERY experienced and could probably diagnose your woes if all else fails.

The HACK · 03-28-2020, 04:32 PM

With the prevalence of phone cameras, it isn't hard to take a video of said action or have a friend take a video. Might be a little easier to see what you're talking about.

wyshyvanuk · 04-17-2020, 11:18 AM

Thanks, guys.
I'll attempt to talk girlfriend into cinematographer roll.
I usually do the work myself, and I haven't tried European Auto Tech. Sounds like an excellent resource, though!!

wdb · 04-17-2020, 03:48 PM

When you say "back and forth" I get confused. Do you mean the car rocks from right to left? Or is the rocking motion up/down, front/rear? Or is it horizontal, does it feel like the body is going front/back horizontally relative to the wheels?

If the motion you feel is significant, it has to be springs/shocks. I can't imagine it being bushings unless something is dreadfully wrong in that regard, so wrong that you'd feel it during regular driving and cornering.

03-22-2020, 08:00 PM	#1
wyshyvanuk Second Lieutenant 449 Rep 229 Posts Drives: 2008 Z4 MR Join Date: Apr 2018 Location: Tucson AZ iTrader: (0)	Z4M Rocks Back and Forth My 2008 Z4M rocks back an forth a couple, three, times when slowly driving over sharp speed bumps. Is that an indication that the rear subframe thingies need replacement, or is it simply normal for the suspension. Thanks for any help!! Ted
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03-23-2020, 09:41 AM	#3
wyshyvanuk Second Lieutenant 449 Rep 229 Posts Drives: 2008 Z4 MR Join Date: Apr 2018 Location: Tucson AZ iTrader: (0)	Sorry, was too lazy to note that the shocks (and struts) were recently replaced with Bilstein B6s. Same back and forth (rather than up and down) motion before and after the replacement.
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03-23-2020, 10:50 AM	#4
garz747 Captain 286 Rep 679 Posts Drives: 07 Z4MC 01 330i 18 X3 M40i Join Date: Jul 2015 Location: Toronto iTrader: (0)	Check for a broken coil spring- not that uncommon.
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03-23-2020, 08:58 PM	#5
wdb dances with roads 4732 Rep 4,096 Posts Drives: '07 E86, '02 996, '95 Seven Join Date: Jul 2015 Location: the perimeter iTrader: (4)	What are the miles on the car?
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03-24-2020, 05:28 PM	#7
wyshyvanuk Second Lieutenant 449 Rep 229 Posts Drives: 2008 Z4 MR Join Date: Apr 2018 Location: Tucson AZ iTrader: (0)	Mileage = 45,000. Didn't check the bushings. Other than the rocking over speed bumps, the suspension seems solid. Thanks!!
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03-25-2020, 12:59 PM	#8
KevinC your average JAMF 3101 Rep 4,094 Posts Drives: '21 M2 Comp, '19 Golf R Join Date: Oct 2005 Location: Cochise County, AZ iTrader: (0) Garage List 2019 VW Golf R [0.00] 2021 BMW M2 Competi ... [0.00]	Who is your mechanic? I use European Auto Tech in Tucson, they've been great. The main BMW dude is VERY experienced and could probably diagnose your woes if all else fails. __________________ '21 M2 Comp '19 Golf R
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03-28-2020, 04:32 PM	#9
The HACK Midlife Crises Racing Silent but Deadly Class 1821 Rep 5,337 Posts Drives: 2006 MZ4C, 2021 Tesla Model 3 Join Date: Oct 2007 Location: Welcome to Jamaica have a nice day iTrader: (1)	With the prevalence of phone cameras, it isn't hard to take a video of said action or have a friend take a video. Might be a little easier to see what you're talking about. __________________ Sitting on a beat-up office chair in front of a 5 year old computer in a basement floor, sipping on stale coffee watching a bunch of meaningless numbers scrolling aimlessly on a dimly lit 19” monitor.
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04-17-2020, 11:18 AM	#10
wyshyvanuk Second Lieutenant 449 Rep 229 Posts Drives: 2008 Z4 MR Join Date: Apr 2018 Location: Tucson AZ iTrader: (0)	Thanks, guys. I'll attempt to talk girlfriend into cinematographer roll. I usually do the work myself, and I haven't tried European Auto Tech. Sounds like an excellent resource, though!!
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04-17-2020, 03:48 PM	#11
wdb dances with roads 4732 Rep 4,096 Posts Drives: '07 E86, '02 996, '95 Seven Join Date: Jul 2015 Location: the perimeter iTrader: (4)	When you say "back and forth" I get confused. Do you mean the car rocks from right to left? Or is the rocking motion up/down, front/rear? Or is it horizontal, does it feel like the body is going front/back horizontally relative to the wheels? If the motion you feel is significant, it has to be springs/shocks. I can't imagine it being bushings unless something is dreadfully wrong in that regard, so wrong that you'd feel it during regular driving and cornering.
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