Drivetrain issue rattle/ chatter/ 6MT e92

[M3nthusiast]

Hello guys and girls!

So I have a '08 92 6MT which has developed some symptoms leading me to believe there is something wrong somewhere in the drivetrain.

Here is a video I uploaded to YouTube which depicts issue #2&3:
https://www.youtube.com/shorts/AcmGfj7eB74

#1: The car sometimes lurches on gear shifts at random, like harsh shifting when unfamiliar with a clutch.

2#: Rattling noise at the bite point when either pressing in or letting out the clutch, which is more prominent at low speeds or when manoeuvring (it seems to subside when you press in the clutch at a slower rate)

#3: Chattering noise and slight feedback through the shifter when shifting, doesn't seem related to #1 as it happens before I release the clutch (intensity seems to vary on occurrences)

#4: Bearing noise in neutral which disappears when pressing on the clutch. (This can also be heard when moving the shifter away from the centre)

#5: When the car is in gear, there is a slight noise (and feedback from the shifter) it happens at random and sounds a little like #3 although is less prominent

Having spent time on the forums trying to diagnose this, some of these issues sound like ones others have had which have been described as 'normal'... I don't believe this to be the case for me as the car has not always sounded like a bag of spanners. LOL

if someone could help me get to the bottom of this it would be awesome... I've gone around in circles thus far with efforts of diagnosis from myself and mechanics, and I want to avoid chasing my tail with unnecessary repair costs (clutch, trans, diff, flywheel) when only one (or neither) of these may be the issue.

Cheers!

[RocketyMan]

Hmmm...in short. How do I put this...?
Those are all normal/typical given mileage and operation.

#1 This depends on how/when you are starting out the transmission to the "kiss point" of the clutch. Not quite sure of your complaint here either as maybe engine operation could play a role into the "lurching" or if you're talking about

#2 Your description of the concern could just be a product of a dual mass flywheel I'm suspecting. Aka, normal. The springs in the DMF do in fact "wear-out" over time. I could amount this complaint to operation.

#3 This is normal. The shifter forks will give feedback when the shifter stalk has pressure on it when there is a "load" on the gear lash, aka the dogs of the slider. You might experience this more because you have a short throw shifter on your setup; more NVH transmitted. Maybe you have poly bushes too?

#4 This is typical "throw-out bearing" noise. In some instances, the dual mass flywheel would need to be replaces since the "springs" on the flywheel can add to the harmonics apparently. This is the story I got from a forum member's experience. There could also be some nuances to the '08 dual mass flywheel to the '09+ versions. I need to do more research myself.

#5 Similar answer/response to #3. Maybe go into more detail on your shifter setup/modifications.


Also keep in mind, driving style may play quite a big role in this as well. The MT seems to have a bit of a warmup period in terms of shifting quality for myself.

[amrazM]

Original clutch and flywheel? no irregular sounds are present in the video, can you redo your video on a good smooth stretch of road so we can take road noise out of the equation.

[Diirek]

Originally Posted by M3nthusiast

Hello guys and girls!

So I have a '08 92 6MT which has developed some symptoms leading me to believe there is something wrong somewhere in the drivetrain.

Here is a video I uploaded to YouTube which depicts issue #2&3:
https://www.youtube.com/shorts/AcmGfj7eB74

#1: The car sometimes lurches on gear shifts at random, like harsh shifting when unfamiliar with a clutch.

2#: Rattling noise at the bite point when either pressing in or letting out the clutch, which is more prominent at low speeds or when manoeuvring (it seems to subside when you press in the clutch at a slower rate)

#3: Chattering noise and slight feedback through the shifter when shifting, doesn't seem related to #1 as it happens before I release the clutch (intensity seems to vary on occurrences)

#4: Bearing noise in neutral which disappears when pressing on the clutch. (This can also be heard when moving the shifter away from the centre)

#5: When the car is in gear, there is a slight noise (and feedback from the shifter) it happens at random and sounds a little like #3 although is less prominent

Having spent time on the forums trying to diagnose this, some of these issues sound like ones others have had which have been described as 'normal'... I don't believe this to be the case for me as the car has not always sounded like a bag of spanners. LOL

if someone could help me get to the bottom of this it would be awesome... I've gone around in circles thus far with efforts of diagnosis from myself and mechanics, and I want to avoid chasing my tail with unnecessary repair costs (clutch, trans, diff, flywheel) when only one (or neither) of these may be the issue.

Cheers!

You ever diagnose the issue? I got something similar going on with my E93.

[Andy1M3]

FWIW my 2008 manual sounds the same. I know the throwout bearing has to be done, and my understanding is there is an updated flywheel and clutch that reduces some noise.

[RocketyMan]

Originally Posted by Andy1M3

FWIW my 2008 manual sounds the same. I know the throwout bearing has to be done, and my understanding is there is an updated flywheel and clutch that reduces some noise.

I would really like to see a parts bulletin or something stating the reason why the 2009+ flywheel/clutch was superseded. It could give some clues and hints to some concerns for OP.

[M3nthusiast]

Originally Posted by RocketyMan

Hmmm...in short. How do I put this...?
Those are all normal/typical given mileage and operation.

#1 This depends on how/when you are starting out the transmission to the "kiss point" of the clutch. Not quite sure of your complaint here either as maybe engine operation could play a role into the "lurching" or if you're talking about

#2 Your description of the concern could just be a product of a dual mass flywheel I'm suspecting. Aka, normal. The springs in the DMF do in fact "wear-out" over time. I could amount this complaint to operation.

#3 This is normal. The shifter forks will give feedback when the shifter stalk has pressure on it when there is a "load" on the gear lash, aka the dogs of the slider. You might experience this more because you have a short throw shifter on your setup; more NVH transmitted. Maybe you have poly bushes too?

#4 This is typical "throw-out bearing" noise. In some instances, the dual mass flywheel would need to be replaces since the "springs" on the flywheel can add to the harmonics apparently. This is the story I got from a forum member's experience. There could also be some nuances to the '08 dual mass flywheel to the '09+ versions. I need to do more research myself.

#5 Similar answer/response to #3. Maybe go into more detail on your shifter setup/modifications.


Also keep in mind, driving style may play quite a big role in this as well. The MT seems to have a bit of a warmup period in terms of shifting quality for myself.

#1 it is certainly not operation i can tell you now, im sure you can understand that when you drive a car everyday you know when something isn’t quite right with the driving dynamics, it’s very clearly to me, an inconsistency with drive engagement.

#2 the car has had a new dmf ~6000 miles ago therefore i doubt this issue would be down to wear and tear considering .

#3 as for polybushes i can’t say.. and the only shifter mod I know of an m5 gear knob itself but I can’t say for sure (this mod was done prior to my ownership)

#4 that may be a possibility yes but i would imagine that noises would be persistent? (Rather than being intermittent)do you know whether the 09+ flywheels are compatible with an 08 car? I would presume that they are interchangeable

Cheers

[M3nthusiast]

Originally Posted by RocketyMan

I would really like to see a parts bulletin or something stating the reason why the 2009+ flywheel/clutch was superseded. It could give some clues and hints to some concerns for OP.

That would be interesting, i believe that size is a factor, although knowing the less apparent would be useful

[M3nthusiast]

Originally Posted by Diirek

You ever diagnose the issue? I got something similar going on with my E93.

I haven’t yet no, has it recently developed on your m3 or has it been present throughout your ownership ?

[RocketyMan]

Originally Posted by M3nthusiast

#1 it is certainly not operation i can tell you now, im sure you can understand that when you drive a car everyday you know when something isn’t quite right with the driving dynamics, it’s very clearly to me, an inconsistency with drive engagement.

#2 the car has had a new dmf ~6000 miles ago therefore i doubt this issue would be down to wear and tear considering .

#3 as for polybushes i can’t say.. and the only shifter mod I know of an m5 gear knob itself but I can’t say for sure (this mod was done prior to my ownership)

#4 that may be a possibility yes but i would imagine that noises would be persistent? (Rather than being intermittent)do you know whether the 09+ flywheels are compatible with an 08 car? I would presume that they are interchangeable

Cheers

#1 This might sound silly buuutt....do you notice any particular temperature this is more apparent at--such as when cold or hot? As an example, when I have a very cold engine, the clutch behavior is drastically different than when the car is warmed up. I can best describe it as "grabby" when cold which maybe is similar to your "lurches" description...?

#2 Yeah I don't think the springs in your DMF wore out already, but simply could just be a product of the feature. The DMF is supposed to have "damper frictions" in the setup.

#3 I wouldn't think the m5 gear knob would have too much to contribute, but maybe something underneath the linkages that you're unaware of?

#4 Yeah the P/N are superseded. I cannot find too much information other that you need to both get a new DMF and clutch when doing this job on older E9x m3 6mts...


Anyway...good info!

[Diirek]

Originally Posted by M3nthusiast

I haven’t yet no, has it recently developed on your m3 or has it been present throughout your ownership ?

I recently purchased it and the noise wasn't present when I got it. It was a one owner car, owned by a professor at MIT that daily'd it. I'm not sure how hard he drove the car but the thing is meticulous.

Anywho, happened after I got used to the car and went on a number of spirited drives. There was an instance when I went to rev match into 2nd and the car did not respond well.... wheels chirped into 2nd and that's probably when I really started hearing it.

[M3nthusiast]

Originally Posted by RocketyMan

#1 This might sound silly buuutt....do you notice any particular temperature this is more apparent at—such as when cold or hot? As an example, when I have a very cold engine, the clutch behavior is drastically different than when the car is warmed up. I can best describe it as "grabby" when cold which maybe is similar to your "lurches" description...?

#2 Yeah I don't think the springs in your DMF wore out already, but simply could just be a product of the feature. The DMF is supposed to have "damper frictions" in the setup.

#3 I wouldn't think the m5 gear knob would have too much to contribute, but maybe something underneath the linkages that you're unaware of?

#4 Yeah the P/N are superseded. I cannot find too much information other that you need to both get a new DMF and clutch when doing this job on older E9x m3 6mts...


Anyway...good info!

#1 It doesn’t seem to matter whether the car is warm or not although i can recall this occuring more when the car is warmed up. It’s not a regularly occurring thing but seems to do it consistently on days where it feels like doing so. The next day, I could get in the car and drive it, and this wouldn’t be an issue whatsoever.. and it could be days/weeks/months before it persists again. “Grabby” would be a good adjective to describe it 👍🏻

#2 Potentially, although again I don’t recall this rattle being present when I purchased the car so I can’t imagine why this is occuring all of a sudden.

#3 It could be possible, honestly i can’t be 100% sure wheter the shift knob is the only modification here, is there anything you could suggest looking at ? One thing I will note is that this only happens when the car is moving and therefore under load, if the car is stationary and I move the shifter in between gears this doesn’t happen (when the engine is turned off, or running with the clutch in).. this being a fact points more towards something beyond the gearbox or shifter assembly to me.. would you agree ?
Although occuring only under load Maybe gearbox mounts ?

I’m lost on this 😭

[M3nthusiast]

Originally Posted by Diirek

I recently purchased it and the noise wasn't present when I got it. It was a one owner car, owned by a professor at MIT that daily'd it. I'm not sure how hard he drove the car but the thing is meticulous.

Anywho, happened after I got used to the car and went on a number of spirited drives. There was an instance when I went to rev match into 2nd and the car did not respond well.... wheels chirped into 2nd and that's probably when I really started hearing it.

What noise is it that’s occuring on your e93? I’m not sure which symptom you’re referring to

[Diirek]

Originally Posted by M3nthusiast

What noise is it that’s occuring on your e93? I’m not sure which symptom you’re referring to

Lurching at low speed in 1st and a slow knocking sound when depressing/releasing the clutch mainly between rev. and 1st. Kind of sounds like something is loose I would say....