328 Manual Transmission Noise

Hey guys, first post ...

I just got a 2010 328i w/ the 6 speed MT. I'm at about 700 miles. It's great!

I did notice a potential irregularity. There is an ever-so-slight rumbling sound when I'm in neutral. The sound goes away if I engage the clutch. The issue might have been there since day one and I might not have noticed it.

Has anyone else experienced this? I'm thinking about calling the dealer tomorrow and see what they say.

Thanks,
Dave

I believe that is normal, and is probably coming from the dual mass flywheel. I've had the same noise in all my BMWs with MT.

I have the same thing. The tech said it was "normal," but wasn't something I expected from a $40k+ car.

Thanks for the responses. After some more "field testing" I've noticed that the noise is more prominent while in neutral and the clutch is partially engaged. The noise is in the form of a small clicking sound. Again, it goes away when the clutch is fully engaged.

Yes, I have that as well in my '09 328 xdrive (see my post of 12/17/09). If you get told anything other than "it's normal," please let us know.

Also, would you mind checking - with your hand or foot - to see if your clutch pedal moves laterally at all while in the released position? Mine moves a few mm to the left and rebounds back to resting position when pushed that way. One dealership said it's normal and another said the clutch should be replaced. Any feedback would be appreciated.

Originally Posted by topgun300

Thanks for the responses. After some more "field testing" I've noticed that the noise is more prominent while in neutral and the clutch is partially engaged. The noise is in the form of a small clicking sound. Again, it goes away when the clutch is fully engaged.

Same with me. In neutral, clutch pedal depressed maybe in inch, sounds like a helicopter.

Mine does the same, but it just happens ever so slightly. Sometimes I don't even notice it, and I usually never have radio,etc on. With radio on, I doubt I could hear it. Only happens in neutral with the clutch off the floor.

It seems to be a bit more pronounced with A/C engaged and I also suspect it to be the dual mass flywheel. It is not a noise that concerns me at all. I think it is rev dependent, because if I recall, giving it a bit of throttle gets rid of it. Cars behave a bit differently at 600 RPM and the drivetrain is not particularly made for 100% smoothness in very very low RPMs.

Originally Posted by jeffjaz

Also, would you mind checking - with your hand or foot - to see if your clutch pedal moves laterally at all while in the released position? Mine moves a few mm to the left and rebounds back to resting position when pushed that way. One dealership said it's normal and another said the clutch should be replaced. Any feedback would be appreciated.

Nope, didn't notice any movement with the clutch petal.

I was told its normal. Crazy, but normal
The "helicopter sound" gets even more pronounced when the car has been driven for some time. Meaning at full operating temp its louder.
Anyone can confirm this?

Originally Posted by razzy530

I was told its normal. Crazy, but normal
The "helicopter sound" gets even more pronounced when the car has been driven for some time. Meaning at full operating temp its louder.
Anyone can confirm this?

Yep, it is louder as the runs. When it first starts up it's not nearly as bad.

Yup, I get this sound also.
Goes away when clutch pedal is pressed.
Normal.

What??? I haven't noticed this at all and I thought I noticed *everything* about my car. Hmmm.... I'll have to check it out while driving tomorrow and report back. I certainly have never heard a helicopter, or even an autogyro.

I haven't noticed any such noise with mine... but then, I try not to ever have the clutch pedal partially depressed.

If I'm correct, if the clutch is all the way in, there's little wear on the clutch and some wear on the clutch bearing. All the way out, and there's no wear on the clutch or bearing. Partially depressed means some wear on the clutch bearing and lots of wear on the clutch. Partially depressed is bad. That's why people who rest their foot, even lightly, on the clutch pedal when driving are damaging their vehicle.

I do not have any of this "noise" in my '09-E93. The normal operation for my car is quite & smooth in all gears and clutch positions. I would be very concerned about this "normal" noise. It seems to me that it may the "normal" way for a clutch to fail. Document it with your SA so that when your car passes 50K you can fight it out with BMWNA.

Just got back from work. Definitely no noise -- I tried it in all various permutations of half-clutch and full-clutch with radio off and window down, even in an enclosed garage to hear better (door open, don't want to succumb to CO.)

No noise like you describe. Anyway, I still do not doubt it could be normal.

We may not be talking about the same noise.

Car in neutral, foot completely off of clutch pedal, there is a slight rattle/noise.
Goes away if you press the clutch pedal.
Often, I can only hear it in the garage where the sound can bounce off the wall.

I believe it is a pressure plate rattle when not under compression.

Originally Posted by Zoltar

We may not be talking about the same noise.

Car in neutral, foot completely off of clutch pedal, there is a slight rattle/noise.
Goes away if you press the clutch pedal.
Often, I can only hear it in the garage where the sound can bounce off the wall.

I believe it is a pressure plate rattle when not under compression.

That is totally normal, in fact, it happens in all the MT cars I've had, the M series more than others, but that's to be expected.

One of the bearings in the clutch. Some techs call it normal.. Some cars don't do it, though and new clutches don't do it either. I had (after some pushing) a clutch put in one of my e90's and one of my e46's due to this noise.

To be clear, the noise you hear sounds like either the gears turning in the transmission or the throw-out bearing rattling.

The tranny noise should be a 'heavier' noise, one that gives the impression of some mass moving around. This noise should stop slowly after the clutch pedal is fully depressed. You can speed the stopping of the internal spinning by depressing the clutch pedal and putting the tranny into gear. This stops all spinning immediately and should help you decide if you are hearing normal tranny noises or the following...

The throw-out bearing rattling noise will be much 'lighter' sounding and should stop with minimum pressure on the clutch pedal. Not enough pressure to weaken the clutch's grip, just enough to take the slack out of the bearing and throw-out bearing arm/pressure plate fingers junctions.

Let us know what does the trick,

Brian

Originally Posted by Zoltar

We may not be talking about the same noise.

Car in neutral, foot completely off of clutch pedal, there is a slight rattle/noise.
Goes away if you press the clutch pedal.
Often, I can only hear it in the garage where the sound can bounce off the wall.

I believe it is a pressure plate rattle when not under compression.

??? I just don't hear any noise in all clutch positions warm or cold engine, just a quiet engine idle. I've driven cars with a really noisy throwout bearing... I wouldn't worry about your particular noise though, sometimes chasing these minor things can make more trouble (e.g. if a tech takes your tranny apart...) Sounds normal to me.

While there is a captive manual tranny audience here, allow me to ask... Is anyone's clutch pedal prone to lateral movement when prodded? No apparent effect on function, but my pedal will move to the left a few millimeters and then return to original place if my foot hits it when it's in the completely released position.

Originally Posted by jaj

While there is a captive manual tranny audience here, allow me to ask... Is anyone's clutch pedal prone to lateral movement when prodded? No apparent effect on function, but my pedal will move to the left a few millimeters and then return to original place if my foot hits it when it's in the completely released position.

A few millimeters? As in approximately 1/16 inch? How would that be perceptible by a normal foot operating the clutch in a normal function?

Mine moves a few millimeters laterally, yes. A few centimeters, no.

I'm starting to think there are a lot of "automobile hypochondriacs" out here...

Originally Posted by jaj

While there is a captive manual tranny audience here, allow me to ask... Is anyone's clutch pedal prone to lateral movement when prodded? No apparent effect on function, but my pedal will move to the left a few millimeters and then return to original place if my foot hits it when it's in the completely released position.

All BMW clutch pedals have some movement, the bushings are not known to be the best. I generally replace mine with the UUC delrin type, it eliminates the movement and ceases the "squeak" that can happen over time.

http://www.uucmotorwerks.com/html_pr..._arm_bushings/

Originally Posted by jaj

While there is a captive manual tranny audience here, allow me to ask... Is anyone's clutch pedal prone to lateral movement when prodded? No apparent effect on function, but my pedal will move to the left a few millimeters and then return to original place if my foot hits it when it's in the completely released position.

Mine had a little 'wiggle' to it, nothing more than sufficient room to let it move freely in normal operation.

Anything more than that, and I'd have a tech look at it.

Originally Posted by neapolitan

A few millimeters? As in approximately 1/16 inch? How would that be perceptible by a normal foot operating the clutch in a normal function?

Mine moves a few millimeters laterally, yes. A few centimeters, no.

I'm starting to think there are a lot of "automobile hypochondriacs" out here...

Sorry Nea if you think I'm overreacting. But yes, it is perceptible to the naked eye and is as opposed to the brake pedal right next door which moves laterally not even a micrometer as I can discern. Additionally, this is something that I never noticed in my prior five years of e46 ownership. I am especially interested to hear from fest members as my local dealer has suggested the clutch pedal be replaced and I am hesitant to have them go and mess with an otherwise finely functioning component - even though it would be covered entirely under warranty - if it's a "normal" phenomenon. Thanks to those of you who responded.