Squeak

I have a 2000 528i with a M52 TU engine. I was hearing what sounds like belt noise while inspecting the belts I found one idler pulley was dry so I replaced all three of them. I still had the noise so I took the belts off and ran the engine still hearing the noise.
What is on or in the engine that could make a noise which sounds like a dried out idler? Seems to be more pronounced when I put the car in gear. (Automatic)

Oh BTY BMW dosen't sell the pulley wheels for the spring loaded tensioners but they will gladly sell you an upgrade for hydralic tensioners at four times the price of a replacement wheel fro the spring type, oh and the special wheel for the hydralic type is extra also.

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Hot off the press not the belts or tensioner pulley's everything replaced, now sounds more like a rattling noise. Coudl the Vanos be making the noise? doesn't sound like it is coming from the front of the engine sound seems to be more pronounced over the intake area.

Hmm?

Originally Posted by Hootman

Oh BTY BMW dosen't sell the pulley wheels for the spring loaded tensioners but they will gladly sell you an upgrade for hydralic tensioners at four times the price

I think it was cn90 who did an autopsy of the so-called hydraulic tensioners (which are just a spring in oil, apparently).

So, the word "upgrade" may be a misnomer in the sentence above.

In addition to not being an upgrade at all, replacing a mechanical tensioner with the so-called hydraulic tensioner has all the problems you mentioned; so I don't know if anyone actually recommends that route.

For details, see:
- How to tell if you have spring-drive or hydraulic belt tensioners or both (1)

Thanks bluebee I do have the mechanical tensioners and I did get replacment pulleys at a local auto store (O'Reilly's) BMW dealer said they were not available anymore and wanted me to upgrade for many hundereds of dollars.
Still trying to find cause of engine noise sounds like a belt or pulley but all new now noise seems to come from driver side of car.

Originally Posted by Hootman

BMW dosen't sell the pulley wheels for the spring loaded tensioners but they will gladly sell you an upgrade for hydralic tensioners at four times the price

Just for cross reference (in case folks come here for information) ...

While BMW won't sell you "just" the pulley for the mechanical tensioners, apparently just the mechanical tensioner pulley "can" be bought separately outside of BMW ...

More information here:
- The difference between hydraulic and mechanical tensioners

this reference to the dayco pulley, if correct, will save me a real headache. the too busy clerk at oreilly's told me the pulley for the hydraulic when (i told him) i have the spring tensioner for my 2000 528iT. I think the squeak was in the alternator (as power steering fluid has been dripping into it for 2 years) and was tempted--given the pulley misorder (its friday and the entire tensioner won't be here until tuesday--ship to ND) to button it all back up having only replaced the alternator and idler pulley.

I am off to carquest to make sure the dayco pulley bolt onto the mechanical spring tensioner.

yea! it fits. Carcraft had two that fit, referencing the Dayco # 89133. One allowed me to use the original 50mm torx; the other had its own (ugly) hex head.