Good Morning,

Apologise it was late and I am getting concerned.

The car is a BMW X5 E53 3.0 Diesel mark 1 on a 2003.

All the belts have been removed and the sound is still there but faint.

I have checked all the pulley and tensioners and replaced them all to be sure.

I put back the old Crank Shaft damper and the sound got worse.

When I bolt on the new crankshaft pulley it quietens down, it is held on with four small bolts instead of one large one.

The sound is like a bearing rattling.

When I put on the serpent belt the noise is there sometimes quite.

Do I need to torque up the bolts to a specific torque?

Once the engine is warm the noise from the front lower appears to disappear.

The PAS has plenty of fluid.

The engine has plenty of oil.

It is turning over find and sound good apart from this annoying random rattly noise.

If it is coming from CrankShaft pukky what could it be?

There are just two belts one for the PAS/Water/Alt, the other powers the A/C.



regards,
Stuart