Thanks Gregory. Sent you a PM.

is the idler wheel the one by the AC Compressor or by the water pump? and i think you can replace the pulleys or the whole unit. what exactly (part number) did you replace. I think i have this EXACT same issue.

Hello,
I changed following items.

1.Waterpump Pulley for No.: 310 025 410 342
2.Water Pump for BMW E36 E46 E91 E34 E39 E60 E61 E38 E65 E66 X3 E No.: 310 024 200 322
3.Tensioner pulley for BMW E36 E46 E34 E39 E60 E61 E38 X3 X5 Z3 Z4 No.: 310 024 870 322
4.CONTI ribbed belt 5PK865 No.: 300 003 650 341
5.Idler Wheel Art.Nr.: 310025320322


They costed me some 130 EUR or so. Water pump is from Saleri (OEM).

I know it is idler wheel, because after removing all these pulleys I checked it. Just rotate and see which one is making noise.

If you want to just change the one that is not good, like someone suggested in this thread. Remove AC belt and serpentine belt and rotate each of these pulleys and observe the noise. Then you will find out.

Mine has done 144K kms, I took this noise as indication these parts are worn out or will be in near future. Labor cost for change of one of these part or all of these parts are almost same hence I did all.

If you want to go for water pump, my advise is go for Saleri (composite propeller) rather other cheap ones with cast iron or plastic propellers. Original water pump taken out from my car also looks exactly like Saleri.

Pls note these part numbers are for my model (EUR). I bought these items on ebay.de from Germany. Before placing order I cross checked all these parts fit my car. In case if you are in Europe, this is the supplier details.

W+S Autoteile GmbH
Schwarzer Weg 10
D-32423 Minden
Deutschland (Germany)

[email protected]
** ws-autoteile.com ** beste Qualitt, Beratung und gnstige Preise


Good luck.

thanks for the info. i am sure it is one of these pulleys or tensioner wheels. i suppose i should go ahead and replace. don't want another failure and serp belt disaster like with my water pump bearing explosion. Literally had ball bearings falling out of the front of the water pump.

hmm....waterpump or any of these pulley noise is an indicator that these parts are going to fail. you can see similar experiences on this forum on water pump failure /engine noise. All they have suggested to replace all these parts in one go, including alternator.

Good luck.

including alternator? never heard that advice before honestly. i figured i would chance it with my tensioners, but am probably on borrowed time. those should be pretty simple to replace thought i'd imagine.

Not necessary to replace water pump or alternator unless they are already causing a problem. A consideration is that you may be tearing it down soon to replace them but there is no way to know that. You can get a sense by input of when others have experienced failure but even then it is just like the actuary tables for our lifetimes we all don't die at the same age. I would be more inclined to replace the water pump if it had over 100,000 miles on it and I had to pay for labor, could not DIY, but that is still a judgment call not a necessity. I would replace all the pulleys with bearings if they were all the same age as the are not expensive parts relatively speaking