BMW X5 E53 (03) Strange metal knocking noise from crankshaft pulley

[jangle]

Good evening All,

Lets set the seen I have already replaced all the pulley and tensioners including the PAS and Air Con pump then I still hear I squeaking noise when the engine starts and stops for no more than 2 seconds.

So I replace teh crack pully and everything would appear ok.

Then 1 week later I turn her on and it sounds like a bearing rattle once she is warm everything is ok.

There is plenty of oil in the system, and when she is warm all is ok.

So checked all wheels on the front, and decide to replace water pump, only thing left is alternator.

Same issue but not as bad.

So run the engine with nothing connected and I hear nothing the issue only occurs when belt connected and under load.

It is winning so far but I refuse to let it win and pass it over to the dealer.

I am more concerned if there is any damage but everything seems ok.

Any advise on the crankshaft would be appreciated.

She has done 122miles and going strong..

Regards,
Stuart

[TwinTurboGTR]

Sorry to hear about your problem. Would you please go into further detail about which E53 you have? Is it a 3.0, 4.4 or 4.6?

Have you connected one belt at a time? I know on the M62, there are separate accessory belts. Try connecting one at a time and see and hear which one is the offender.

[cn90]

1+,

When posting problem, you need to specify the model/engine.

Remove all the belts, and spin ALL pulleys by hand (idler, tensioner x2, WP, alternator, AC pulley etc.).

A bad pulley will free-wheel.

[jangle]

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