Hello!
i'll try to be brief, without any emotions about this situation
Course, my car is R53, about 100.000 miles. Because of end of stock clutch, I've decided to resolve this problem globally. Plus some other preventive operations:
- TTV lightened flywheel (http://www.lohen.co.uk/shop/products.php?cat=20)

- Helix performance clutch (http://www.lohen.co.uk/shop/proddeta...HelixClutchkit)

- Crank pulley (http://cgi.ebay.com/ebaymotors/BMW-M...Q5fAccessories)

- Powerflex gearbox mounting bush (http://www.lohen.co.uk/shop/proddeta...oxMountingBush)



And the result (if clutch pedal is pressed there is no any noise)

http://www.youtube.com/v/xMEwJ9wygbU

What shall I do?

 

Since the flywheel is a single mass it will chatter at idle. Nothing to worry about except for the crank pulley you need to put either a new OEM damper pulley on or an Ati Damper.

 

about flywheel - well, I hope so. Will see how long it will be OK.
about pulley and damper - don't think that it is useful device. Especially for 400$...

 

Like checkmate said, that's perfectly normal for a lightened flywheel setup and is nothing to worry about... I've been dealing with that same knocking for almost 40k miles. And as you noticed in the video, the knocking will stop when the clutch is depressed.

GotMINI

 

I forgot to mention I have clutchmasters aluminum lightweight flywheel and FX400 6-puck sprung clutch in my car. It also does this chatter its just the nature of the single mass flywheel. Now the reason the factory doesn't chatter is because its dual mass. The use of the OEM or Ati damper is so the crankshaft has counter weighted balance on both ends especially in the case of a lighten flywheel. Since you have lighten both your introducing higher levels of harmonics through the motor which is bad.

 

Forget everything I just said, the picture is of a solid hub clutch plate when the teｘｔ says sprung. Either way GEARBOX chatter is the reason BMW went with the dual mass.

 

^^ and it is LOOOUUUDDDDDD! haha. i just went from a clutchmaster back to stock cause im prepping the car to sell and i forgot how loud that flywheel made the car. revs slow as ***** now though :( That is clutch chatter and gearbox chatter when you decelerate though, its fine.
You should get an ati crank pulley though, its either 400 now or $XXXX later when you ruin your main bearings and have to rip the bottom end apart and replace stuff.