You just need to get a thin wire or compress air such as for cleaning the keyboards on computers and locate the condensate line underneath the truck and clear the line.

As for you video on Youtube, that will definitely not win any awards. :rofl:

Fan should be rotating--check if belt is moving and something driven by the belt is not. If belt is not moving than one of the pulleys driven by the belt is frozen or the belt is loose or about to break.

Over weekend when I looked at, noise is apparent when car engine is on and vehicle is not moving. So this could be Idler Wheel.


Any suggestions how to confirm this?

One option is to remove the serpentine belt and spin the pulley. If bad, you will be able to tell by the sound it makes when you spin it. If bad, it will spin easily and sounds like it needs oil.

The following is an example of what a bad pulley can sound like: Sound of BAD Pulley on 1998 528i (E39) - YouTube

One option is to remove the serpentine belt and spin the pulley. If bad, you will be able to tell by the sound it makes when you spin it. If bad, it will spin easily and sounds like it needs oil.

The following is an example of what a bad pulley can sound like: Sound of BAD Pulley on 1998 528i (E39) - YouTube

Thanks for all replies.

Finally it turn out idler wheel.

But I changed

Idler wheel,
Alternator Belt, AC Belt
Water pump (Saleri SIL) - This has composite impeller, this looks same as one taken out from car, I mean the original part.

Along with the Servicing (Inspection 1)

All parts bought from ebay.de for around Eur 130.00

Onemore extension to this topic,

to change the water pump, radiator needs to be removed, drained and fit it back.

My observation is, mechanic has filled the coolant to required level. After I drove 50 km it gave me check coolant level message on computer panel.

Then I top it up 500ml normal water. Then the next morning when I saw level indicator stick is at lower level. I filled again and drove some 20 kms then again indicator stick is at lower level. after driving for another 20 kms it is again at normal level. No message though.

I cannot see any water dripping on floor. Even I left it for whole night and some 4-5 hours at work after driving in morning.


I am guessing it must be bubbles when coolant was filled.

Any ideas? or past experiences?

Your mechanic (where are you, I'm in Geneva) may not know the procedure to bleed air from the heater of a more modern E53. It is likely that your one or two drives took care of this. I'd suggest you run 5 to 15 minutes with the engine warm and the heater at max temp to fully cover this. There is also an air bleeder screw at the top of the radiator to evacuate any air in the system.

Hi Gregory891,

Thanks for reply. I am in Zurich. What I found this morning is, plastic screw on connector tube, next to radiator cap is torn out. After driving for few mins I can see water on this screw. Had get this changed. Let me check for few more days.

That screw is the bleeder screw for the system. You can replace with a new one (cheap from a BMW dealer), the other known upgrade part is the same in brass (then it doesn't get stuck / welded over time).

If you have other questions or recommendations, drop me a PM.