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      08-02-2017, 03:48 PM   #1
topdawgx99
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Thunk sound in driver rear

Hey guys,

I installed some coilovers... and everything was perfect for about 3 weeks. After 3 weeks, I started hearing a thunk sound in the driver rear side, sounds like near the wheel well. It happens during normal driving, more prevalent with bumps. Whenever I lift the car, take a look, and lower it again, the sound goes away for maybe 5 miles before it comes back. I made sure all the nuts and bolts are tight, there is a gasket where the struts connect to car. Does anybody have any ideas what this may be?

It's hard to describe the exact sound, but maybe like a dull sound, almost like a dull larger metal piece is bouncing inside the frame (not really that, but sounds like that)
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      09-25-2017, 04:44 PM   #2
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2007 Z4 M COUPE  [4.50]
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Originally Posted by topdawgx99 View Post
Hey guys,

I installed some coilovers... and everything was perfect for about 3 weeks. After 3 weeks, I started hearing a thunk sound in the driver rear side, sounds like near the wheel well. It happens during normal driving, more prevalent with bumps. Whenever I lift the car, take a look, and lower it again, the sound goes away for maybe 5 miles before it comes back. I made sure all the nuts and bolts are tight, there is a gasket where the struts connect to car. Does anybody have any ideas what this may be?

It's hard to describe the exact sound, but maybe like a dull sound, almost like a dull larger metal piece is bouncing inside the frame (not really that, but sounds like that)
Did you replace out Rear shock mounts when you installed the coilovers or did you keep the stock ones? Also did your coilovers kit come with new bump stops?

I'm assuming you had to remove the trim panels in the rear to install the shocks, could it be a loose Tim panel?
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      09-25-2017, 08:50 PM   #3
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If you used the OEM shock mounts for your coil overs, it's likely that you've blown out the center rubber bushing on one of them. The OEM shock mounts are designed to take the force of the shocks but not to support the weight of the car long term. You need to look at changing to something like the Rogue Engineering mounts and also need to look at reinforcements for the body sheet metal where the shock mounts are located as that area isn't designed to be weight bearing either. Without reinforcement that area will eventually start to develop stress fractures in the sheet metal and it takes some expensive welding to repair that.
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      09-28-2017, 01:24 AM   #4
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If u need new rear shock mounts let me know. I have a like new set from TC Kline for sale.
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