knock knock knocking.....

[fatty]

i have a 95 328i and it has started to knock.....
when the engine is ticking over you can hear a faint knocking noise, but when you press the clutch i the noise stops.......
.........is this my clutch bearing?

[Dave at Pelican Parts]

It's possible that it is your throwout bearing. Another possibility (one that happened on my "other car") is that a transmission input shaft bearing is going out. I'm sure there are other possibilities, but I can't think offhand of what they could be.

--DD

[Wayne 962]

Do you ride the clutch a lot? This can wear out the main thrust bearings on the crankshaft. Not likely, but a possibility.

Sounds like a throw-out bearing issue to me too. Does it change slightly when you press the clutch slightly, or is it more on-and-off?

-Wayne

[Dave at Pelican Parts]

The symptoms when the input shaft bearing went were:
The drivetrain made a rattling noise at idle. When you pushed the clutch pedal in, the rattling slowed down and stopped. I later noticed that the rattle was also there when the car was in gear, or at higher RPMs, but the other noise covered up the rattle.

The stuff that spins when the transmission is in neutral and stops when the clutch is let out is the transmission input shaft, and all the stuff that is connected to the input shaft. Which means the clutch disk, and stuff that is inside the transmission. Depending on the exact design of the clutch throwout mechanism in the BMW, the throwout bearing could be spinning with the clutch disk or it could be still relative to the disk.

Hopefully your problem is cheaper than mine was...

--DD