For a few months now I've been getting a noise that I can really only describe as a "tink" or "marble hitting a tin can" on my 96 m3. I've had the car for a year and a half now (2nd owner), the engine and drive are bone stock as far as I know, and the car has 132k on the clock.
I hear the noise when engaging or disengaging the clutch in any gear, when the car changes momentum. I don't hear it engaging / releasing the clutch in neutral. Since I don't hear it out of gear or rolling in neutral, I'm not inclined to believe it is any of the components behind the transmission.
Previously I've examined the flex disc, the drive shaft, differential, center support bearing, and rear axles. Separately, the Vanos has been replaced recently and the noise I hear now is quite different from that noise.
My best theory right now is there is slop or a loose component on either the clutch/flywheel or transmission. I don't have too much experience diagnosing manual transmissions, but I have heard flywheel noise is not uncommon. Two German mechanics (which I believe have sufficient experience working on these cars) do not believe the noise is indicative of a mechanical problem, and without pulling the clutch/transmission I'm not sure if I can further diagnose it. Obviously I'd prefer not to spend the time, money, and effort pulling the clutch/flywheel if I can avoid it.
Has anyone else had these symptoms on their e36 or have any insight on what the problem may be?. I appreciate any advice you may have, and thank you in advance for the responses.