Rattle noise goes away when clutch engaged

[jkoral]

Noticed a new noise after an hour commute in warm temps (75 F). I was sitting right next to a tall brick wall with the window open (drive through).

When I pushed in the clutch pedal I noticed a slight rattling noise go away and become silent. Letting out the clutch (but remaining in neutral), I could hear that rattling.

I've done my share commuting in stop and go traffic and have never noticed this before. I just turned 42K miles on my 2009.

The only reference I found here on 1addicts was the 3rd/4th paragraph here: http://www.1addicts.com/forums/showthread.php?t=604139

"Also, intermittently when standing at a robot and no gear engaged there is another rattly sound, something like a loose bolt rattling, when I engage clutch (no gear) it goes away, this leads me to believe its the release bearing. The car has under 15000 miles and is a 2008/2009."

I found a similar thread on ZHP Mafia (E46), and it kinda sounds like this:

but it not *nearly* as loud. I'm not sure how long it's been doing it, but the combination of being right next to a full height brick wall with my window open made it noticeable. With the windows up and stereo on, it is imperceptible.

Any ideas?

[RaceTruk]

Prob flywheel
While you release clutch while in neutral, try just pushing the shifter forward without going into gear.
If the noise goes away it is likley your flywheel springs have gotten worn.
It will not affect performance it just sounds like shit.

[2tonik]

I thought this was the sound of the bearings in the transmission making noise.

[jkoral]

Originally Posted by RaceTruk

While you release clutch while in neutral, try just pushing the shifter forward without going into gear.
If the noise goes away it is likley your flywheel springs have gotten worn.

Thanks -- I tried this but the noise does not go away.

It sounds very similar to videos I find of BMWs that replaced the dual mass flywheel with a single-mass/lightweight flywheel.

It's like a faint chattering. I can only hear it when the clutch is engaged (out) and I'm idling in neutral. I don't notice it on startup, but when I reach my destination and I'm parking (or backing up). I assume the higher revs on cold start mask or make the noise go away.

FWIW, I'm very gentle on the clutch, no drag racing or hard starts with slipping the clutch.

[Dackelone]

This noise is NORMAL. All dual mass flywheels will make "some" noise. Also as your cluch springs become slightly "compressed" they will rattle at idle or just off idle. Its not hurting anything, don't be too concerned over this noise.

[jkoral]

Originally Posted by Dackelone

This noise is NORMAL. All dual mass flywheels will make "some" noise. Also as your cluch springs become slightly "compressed" they will rattle at idle or just off idle. Its not hurting anything, don't be too concerned over this noise.

Thanks Dack. I'll take your word for it because I'm off warranty and certainly not planning on touching the clutch or flywheel any time soon. I just wanted to prove to myself what the noise was since it just started recently (especially now that I have my windows open in spring).

Like many enthusiasts on here, I'm always listening for new noises.

[GMD]

My car does the same thing. I thought it was a bearing or something. Good to hear it's normal!!

[Wakka]

ditto. noticed it last month for the first time. its *VERY* faint.

[jkoral]

Good video clip of the noise in this thread:
http://www.1addicts.com/forums/showp...6&postcount=23

This is my 4th manual tranny BMW and never encountered this sound before (they all had dual mass flywheels).