Noise from drivetrain

MBMW · 08-20-2024, 06:15 AM

I posted this question in the M6 forum, but not getting any answers. I figured I post here as well since the M5 and M6 are the same.

I'm getting a thud (bang) when on I'm off and on the accelerator. It happen in sport mode but not all the time. is this part of the cars charm (normal)?

It's M6 MY17 with 29K km on it so far, car is stock. Had the diff main seal replaced due to a leak when I first got it. The work was done at a BMW dealer.

Is this normal or I should take it back to dealer?

M5Rick · 08-20-2024, 06:26 AM

Take back to dealer, and have the diff holder checked for cracking.

Boosted M5 · 08-20-2024, 10:22 PM

Yep, sounds like diff bushings are done or almost done. Mine is starting to do it and I’m at 66k.

MBMW · 08-22-2024, 04:39 AM

I appreciate the replies and advice. I did a full pre purchase inspection, diff bushes are good nothing wrong with the vehicle except the diff leak which was repaired by a BMW dealer. Since then I only drove the car 500km. I doubt the diff carrier or bushes are cracked.

will take it back for inspection and report back.

M5Rick · 08-22-2024, 05:30 AM

Best put it on a rolling road and test it there.

MBMW · 08-28-2024, 08:38 AM

Quote:

Originally Posted by M5Rick

Best put it on a rolling road and test it there.

Do you mean curved road?

MBMW · 09-10-2024, 10:15 AM

The car is at the dealer, checked backlash, removed proper shaft, checked transmission, bushes, suspension, everything within spec and guess what noise is still there.

M5Rick · 09-10-2024, 10:43 AM

Quote:

Originally Posted by MBMW

Do you mean curved road?

No, rollers in garage testing for hp and brake testing.

Singh_96 · 09-14-2024, 01:22 PM

most of these cars do it, i've been in 3 and they all had the slight thud, mostly only noticeable in sport plus and 3rd gear lower speeds getting on and off

MBMW · 09-16-2024, 06:33 AM

Dealer opened a case with Germany, they received instruction to check certain parts and run test, which they've done. Same noise before and after.

Luckily, another M6 came for service, it has the same noise and driving behavior.

Conclusion: normal car characteristics

KurtsM5 · 09-17-2024, 06:36 AM

Quote:

Originally Posted by M5Rick

No, rollers in garage testing for hp and brake testing.

Dyno?

08-20-2024, 06:15 AM	#1
MBMW Private First Class 14 Rep 106 Posts Drives: 2017 M6 coupe Join Date: Aug 2010 Location: Dubai UAE iTrader: (0)	Noise from drivetrain I posted this question in the M6 forum, but not getting any answers. I figured I post here as well since the M5 and M6 are the same. I'm getting a thud (bang) when on I'm off and on the accelerator. It happen in sport mode but not all the time. is this part of the cars charm (normal)? It's M6 MY17 with 29K km on it so far, car is stock. Had the diff main seal replaced due to a leak when I first got it. The work was done at a BMW dealer. Is this normal or I should take it back to dealer?
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08-20-2024, 06:26 AM	#2
M5Rick General 66675 Rep 21,553 Posts Drives: M5 F10 DCT Gunmetal Join Date: Aug 2018 Location: GB iTrader: (0)	Take back to dealer, and have the diff holder checked for cracking.
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08-20-2024, 10:22 PM	#3
Boosted M5 Private First Class 73 Rep 196 Posts Drives: F10 m5 Join Date: Dec 2018 Location: Sf bay area iTrader: (0)	Yep, sounds like diff bushings are done or almost done. Mine is starting to do it and I’m at 66k.
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08-22-2024, 04:39 AM	#4
MBMW Private First Class 14 Rep 106 Posts Drives: 2017 M6 coupe Join Date: Aug 2010 Location: Dubai UAE iTrader: (0)	I appreciate the replies and advice. I did a full pre purchase inspection, diff bushes are good nothing wrong with the vehicle except the diff leak which was repaired by a BMW dealer. Since then I only drove the car 500km. I doubt the diff carrier or bushes are cracked. will take it back for inspection and report back.
	Appreciate 0 Quote

08-22-2024, 05:30 AM	#5
M5Rick General 66675 Rep 21,553 Posts Drives: M5 F10 DCT Gunmetal Join Date: Aug 2018 Location: GB iTrader: (0)	Best put it on a rolling road and test it there.
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09-10-2024, 10:15 AM	#7
MBMW Private First Class 14 Rep 106 Posts Drives: 2017 M6 coupe Join Date: Aug 2010 Location: Dubai UAE iTrader: (0)	The car is at the dealer, checked backlash, removed proper shaft, checked transmission, bushes, suspension, everything within spec and guess what noise is still there.
	Appreciate 0 Quote

09-14-2024, 01:22 PM	#9
Singh_96 Private First Class 39 Rep 116 Posts Drives: F06 M6 \|\| E90 335i \|\| F15 X5 Join Date: Jul 2017 Location: New Jersey iTrader: (3)	most of these cars do it, i've been in 3 and they all had the slight thud, mostly only noticeable in sport plus and 3rd gear lower speeds getting on and off
	Appreciate 0 Quote

09-16-2024, 06:33 AM	#10
MBMW Private First Class 14 Rep 106 Posts Drives: 2017 M6 coupe Join Date: Aug 2010 Location: Dubai UAE iTrader: (0)	Dealer opened a case with Germany, they received instruction to check certain parts and run test, which they've done. Same noise before and after. Luckily, another M6 came for service, it has the same noise and driving behavior. Conclusion: normal car characteristics
	Appreciate 0 Quote