FYI. Rattle/Clunk In Drivetrain Of 2012 M3

baba louey · 10-02-2012, 07:42 PM

In case anyone is interested. I've had my M3 since July and from day one I detected an odd little rattle/clunk coming from under the mid-section of the car while going very slowly and engaging/disengaging the clutch. I took the car in for the 2K service and mention the noise. The technician said that was normal for my car. I had the service manager confirm this again while he and I were in the car. Being a skeptical kinda guy, I asked to drive a new manual M3 that was on their lot and sure enough I could produce the same rattle/clunk. Seems that it is some gear in the transmission that vibrates (rocks back and forth) a bit under certain low, slow power transfers (slow clutch engagement). I am resting easier now and have to say that the dealer treated me very well and dealt with all my requests.

BMRLVR · 10-07-2012, 02:44 AM

This is a known thing, and there is even mention of unusual noises being normal for the M3 in your owners manual.

baba louey · 10-08-2012, 10:25 AM

Yes, I read that in the manual the day after I got the car. A friend of mine has had 2 M3's and 2 M5's. When he drove the car, he mentioned the noise. All of his cars were auto-manuals. I really appreciated the dealer getting another M3 out for me.

I'm always suspicious when I hear the words "That's normal for the car". In this case the words were true. Extra points for the dealership on this one.

ep99 · 10-11-2012, 01:59 AM

There was a service bulletin on differential noise when doing slow turns.

It happened to my 2009 M3 coupe with DCT.

Took the car out with the technician and we have to do slow figure 8 turn in an empty parking lot to recreate the grinding noise.

baba louey · 10-11-2012, 12:52 PM

I've been made aware of the diff noise from several sources. At my 2k service, the shop put in the diff lube with a slipperier additive. There has been discussion in the general forum whether the additive lessens the effectiveness of the LSD, but it seems to reduce the noise. I've installed LSD's on a couple of the cars that I've owned and at least one of them made a noise when turning tightly. This was considered normal by the diff manufacturer. My noise was coming from the transmission.

Puckmaster · 10-16-2012, 11:48 AM

My 08 DCT makes a small clunk when it gears down from 2nd to 1st. Told it was normal for a DCT, so I just live with it. Looking forward to trying the 13 V10 R8 with the new 7 speed double clutch. If it is as good as M, I will be making the switch

baba louey · 10-16-2012, 02:46 PM

My friend (who drove my manual) with a 2011 DCT M3 said he didn't hear any noise from his trans.

I test drove the new 911 with 7 speed DCT and it shifted great. Porsche converted this transmission into the first 7 speed manual for a car. I didn't have the chance to drive the 911 manual. I'm sure the R8 will be fantastic. A bit pricier though.

10-02-2012, 07:42 PM	#1
baba louey First Lieutenant 64 Rep 303 Posts Drives: 2012 M3 6sp ZCP Mel red coupe Join Date: Aug 2012 Location: calgary iTrader: (0)	FYI. Rattle/Clunk In Drivetrain Of 2012 M3 In case anyone is interested. I've had my M3 since July and from day one I detected an odd little rattle/clunk coming from under the mid-section of the car while going very slowly and engaging/disengaging the clutch. I took the car in for the 2K service and mention the noise. The technician said that was normal for my car. I had the service manager confirm this again while he and I were in the car. Being a skeptical kinda guy, I asked to drive a new manual M3 that was on their lot and sure enough I could produce the same rattle/clunk. Seems that it is some gear in the transmission that vibrates (rocks back and forth) a bit under certain low, slow power transfers (slow clutch engagement). I am resting easier now and have to say that the dealer treated me very well and dealt with all my requests.
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10-07-2012, 02:44 AM	#2
BMRLVR Grease Monkey 295 Rep 2,646 Posts Drives: 2011 E90 M3,1994 Euro E36 M3/4 Join Date: Apr 2006 Location: Fort McMurray, Alberta, Canada iTrader: (3)	This is a known thing, and there is even mention of unusual noises being normal for the M3 in your owners manual. __________________ 2011 E90 M3 ZCP - Individual Moonstone/Individual Amarone Extended/Individual Piano Black With Inlay:LINK!!! 1994 Euro E36 M3 Sedan - Daytona Violet/Mulberry:LINK!!!
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10-08-2012, 10:25 AM	#3
baba louey First Lieutenant 64 Rep 303 Posts Drives: 2012 M3 6sp ZCP Mel red coupe Join Date: Aug 2012 Location: calgary iTrader: (0)	Yes, I read that in the manual the day after I got the car. A friend of mine has had 2 M3's and 2 M5's. When he drove the car, he mentioned the noise. All of his cars were auto-manuals. I really appreciated the dealer getting another M3 out for me. I'm always suspicious when I hear the words "That's normal for the car". In this case the words were true. Extra points for the dealership on this one.
	Appreciate 0 Quote

10-11-2012, 01:59 AM	#4
ep99 Second Lieutenant 41 Rep 200 Posts Drives: 2024 M4 Competition xDrive Join Date: Aug 2009 Location: Toronto iTrader: (0)	There was a service bulletin on differential noise when doing slow turns. It happened to my 2009 M3 coupe with DCT. Took the car out with the technician and we have to do slow figure 8 turn in an empty parking lot to recreate the grinding noise.
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10-11-2012, 12:52 PM	#5
baba louey First Lieutenant 64 Rep 303 Posts Drives: 2012 M3 6sp ZCP Mel red coupe Join Date: Aug 2012 Location: calgary iTrader: (0)	I've been made aware of the diff noise from several sources. At my 2k service, the shop put in the diff lube with a slipperier additive. There has been discussion in the general forum whether the additive lessens the effectiveness of the LSD, but it seems to reduce the noise. I've installed LSD's on a couple of the cars that I've owned and at least one of them made a noise when turning tightly. This was considered normal by the diff manufacturer. My noise was coming from the transmission.
	Appreciate 0 Quote

10-16-2012, 11:48 AM	#6
Puckmaster Private First Class 4 Rep 154 Posts Drives: White 2008 E92 M3 Coupe DCT Join Date: Dec 2009 Location: Edmonton, Canada iTrader: (1) Garage List 2012 McLaren MP4-12C [0.00]	My 08 DCT makes a small clunk when it gears down from 2nd to 1st. Told it was normal for a DCT, so I just live with it. Looking forward to trying the 13 V10 R8 with the new 7 speed double clutch. If it is as good as M, I will be making the switch
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10-16-2012, 02:46 PM	#7
baba louey First Lieutenant 64 Rep 303 Posts Drives: 2012 M3 6sp ZCP Mel red coupe Join Date: Aug 2012 Location: calgary iTrader: (0)	My friend (who drove my manual) with a 2011 DCT M3 said he didn't hear any noise from his trans. I test drove the new 911 with 7 speed DCT and it shifted great. Porsche converted this transmission into the first 7 speed manual for a car. I didn't have the chance to drive the 911 manual. I'm sure the R8 will be fantastic. A bit pricier though.
	Appreciate 0 Quote