Need Advice

badbimmer · 12-13-2010, 06:03 PM

Hi all, I've been lurking here for awhile and need some advice. My 2008 M3 is at the dealer b/c I am having 2 issues:

1) After high revs, when I let go of the gas during engine breaking my car developed a sporadic vibration or rumble as the revs drop. Feels liks something in the drivetrain

2) When I let off the gas I get a thump, not something you can hear, just something you can feel, feels like the diff or ujoint issue.

The dealership did not find anything after an inspection and wants me to reproduce. But it's sporadic and doesnt happen consistently.

Not sure what to do. It a real pain in the a!*(*&^

-BB

badbimmer · 12-16-2010, 07:05 AM

No one? anyone experienceing these issues?

elh0102 · 12-16-2010, 07:54 AM

It does sound diff or U-joint related. The fact it is intermittent makes diagnosis challenging, and you may have to let it get worse before it can be fixed. If the differential has not been serviced, then it would not be wasted money to get that done, on the slight chance it is a lubricant issue. And the U-joints can be inspected for wear and excessive tolerence.

12-13-2010, 06:03 PM	#1
badbimmer Second Lieutenant 47 Rep 241 Posts Drives: E92 M3 White/Fox Red CF Join Date: Dec 2010 Location: NY iTrader: (3)	Need Advice Hi all, I've been lurking here for awhile and need some advice. My 2008 M3 is at the dealer b/c I am having 2 issues: 1) After high revs, when I let go of the gas during engine breaking my car developed a sporadic vibration or rumble as the revs drop. Feels liks something in the drivetrain 2) When I let off the gas I get a thump, not something you can hear, just something you can feel, feels like the diff or ujoint issue. The dealership did not find anything after an inspection and wants me to reproduce. But it's sporadic and doesnt happen consistently. Not sure what to do. It a real pain in the a!(&^ -BB
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12-16-2010, 07:05 AM	#2
badbimmer Second Lieutenant 47 Rep 241 Posts Drives: E92 M3 White/Fox Red CF Join Date: Dec 2010 Location: NY iTrader: (3)	No one? anyone experienceing these issues?
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12-16-2010, 07:54 AM	#3
elh0102 Captain 15 Rep 751 Posts Drives: 2009 335i coupe Join Date: Apr 2010 Location: USA iTrader: (0)	It does sound diff or U-joint related. The fact it is intermittent makes diagnosis challenging, and you may have to let it get worse before it can be fixed. If the differential has not been serviced, then it would not be wasted money to get that done, on the slight chance it is a lubricant issue. And the U-joints can be inspected for wear and excessive tolerence.
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