Any ideas...?

Car drives fine however when clutch is disengaged (pedal down) there is a loud rotational knocking/rattling which seems to come from the entire powertrain. Does this in neutral or with any gear engaged. Car stationary or moving. On releasing the pedal it goes quiet. Clutch function is normal.

Noise goes away if the engine is reved to 1500+ rpm. Also goes away if clutch is released to the point where is just bites. It is loudest when the pedal is fully depressed. Sounds like a failing DMF but this car doesn't have a DMF. Seems much too loud to be a release bearing...

sounds like release bearing, bearing badly worn could be flexing on pressure plate fingers causing the knock if left long enough they can start breaking up, primary shaft bearing is another possible, strip down is required to find out!

Thanks for your reply. Its a really nasty rattling/knocking when the clutch pedal is pressed down. If the car is stationary and I engage a gear with the clutch down (so that the gearbox input shaft is held stationary) the knocking doesn't change. So I think its not the gearbox. Most likely the clutch - I hope. Is there any way it could be a loose flywheel.?

Flywheel attachment bolts usually have locking tabs to ensure they stay tight. If you don't have a DMF then as suggested it may be the clutch or release bearing.

Edited by galileo on 10/03/2021 at 15:11

Any ideas...?

Car drives fine however when clutch is disengaged (pedal down) there is a loud rotational knocking/rattling which seems to come from the entire powertrain. Does this in neutral or with any gear engaged. Car stationary or moving. On releasing the pedal it goes quiet. Clutch function is normal.

Noise goes away if the engine is reved to 1500+ rpm. Also goes away if clutch is released to the point where is just bites. It is loudest when the pedal is fully depressed. Sounds like a failing DMF but this car doesn't have a DMF. Seems much too loud to be a release bearing...

sounds like release bearing, bearing badly worn could be flexing on pressure plate fingers causing the knock if left long enough they can start breaking up, primary shaft bearing is another possible, strip down is required to find out!

Thanks for your reply. Its a really nasty rattling/knocking when the clutch pedal is pressed down. If the car is stationary and I engage a gear with the clutch down (so that the gearbox input shaft is held stationary) the knocking doesn't change. So I think its not the gearbox. Most likely the clutch - I hope. Is there any way it could be a loose flywheel.?

its more likely the release bearing is breaking up and knocking on the pressure plate fingers, problem will be the amount of damage occurring to the pressure plate will destroy the fingers and will not allow you to change gear at all

unlikely to be loose flywheel, needs dismantling to find out, let us know how you get on!