I've got my blacktop 1.8 up and running, at anything above a slow idle the engine sounds fine and has excellent oil pressure, no nasty smoke or rattles.

But at idle there is a loud knocking, which stops if I press the clutch, I'm thinking this is either a noisy thrust bearing, or crankshaft end float. Anyone had a similar problem, or ideas as to what could be wrong? Blacktop MT75, 2.0L DOHC clutch and thrust bearing....

[Edited on 22/11/08 by r1_pete]

Are you certain its the engine, could it be a transmission rattle that stops when the gears stop spinning after depressing the clutch, or the release brg rattling until loaded up when pressed.

Mines does that - pretty sure it's the transmission hitting the chassis in my case....

[Edited on 22/11/08 by stevebubs]

Clutch ? On Fords tintop the clutch thrust bearing is normally held in light contact with the clutch pressure plate not so if you have a home made clutch pedal. --- could be a little run out in the clutch is knocking on the release bearing.

To locate where the noise is comming from use either a tube as a sethoscope or a large screw driver or hammer shaft (ie hold the shaft against various bits of the engine/gearbox and put your ear to the opposite end.

[Edited on 22/11/08 by britishtrident]