Pulley noise, whinning, which pulley is it ?

[Panchoz3]

Pulley noise, whinning, which pulley is it ?

Pitch changes relevant to rpm''s in park or stopped in neutral.
I think it''s a pulley. Does anyone have info re. which pulley to
check, or what else could be the source of the problem ?

Thanks

[Panchoz3]

I'd post a follow up and tell you how to diagnose and repair the problem, except, considering that there has not been even one response in 8 weeks, it's obvious that no one reads this forum.

[eclass]

look at the power steering reservoir, first is the fluid level full? With the reservoir full and the engine running you should Not see alot of movement of the fluid. If it looks like it is swirling around then the reservoir needs to be replaced, cheep part, easy to replace. Other than that it will be up to you to listen for the location of the noise.

[Panchoz3]

Replaced pulley.
Problem solved.

Used steth. Noise clearly came from idler pulley (MB calls it a guide pulley), not tensioner pulley, steering pump, alternator, or fan.

Picked up MB part #0002020019, $31.20.

Note: Using the "loosen clips & remove inner grill & and push radiator and condenser forward to make room to remove pulley bolt" technique, I ran into problem--not enough room to remove bolt unless the plastic pulley is broken away. My pulley did not fail and fall to pieces like others on this forum have. That was not my problem. My problem was that the pulley was intact, but was making too much noise, and had to be replaced. To have enough room to remove the pulley, using the above mentioned technique, I had to use a pair of big channel locks, and crunch up my noisy pulley into pieces, and then I was able to remove the bolt. After that ordeal, the rest of the job was easy.

A warning: Be careful after you remove the radiator retention clips, because it is easy to break the fragile plastic tabs that the clips mount on to. They stick out, and you can snap them off if you bump them or lean on them while you are working on the pulley. For such an expensive car, it has a lot of crappy overly fragile plastic parts.