Ford Focus mk1 (98-04) 1.8 TDCi manual - Noisy at higher speeds stops when clutch depressed - Opiquaq

The noise starts at 50mph or thereabouts and sounds like a vibrational rrrrrrrrr type of noise - consistent, gradually louder with speed, no noticeable vibration in the cabin and stops when the clutch is depressed. It isn't very loud, but it is definitely new! Does anybody have any ideas of what it could be?

Ford Focus mk1 (98-04) 1.8 TDCi manual - Noisy at higher speeds stops when clutch depressed - Oli rag

Sounds like a gearbox bearing problem, a worn clutch release bearing usually gets noisy when the pedal is pressed. The release bearing wouldn't really be affected by road speed.

Ford Focus mk1 (98-04) 1.8 TDCi manual - Noisy at higher speeds stops when clutch depressed - Opiquaq

thanks for the thinking