so the saga continues...

Turning on the engine yesterday (89 S4)..and all seems good. Hit AC button and squelling and cluncking noise. Turn it off, it is gone....and so on.... Great!!!!

After looking into it, the noise seems to be coming from the passenger side cooling fan. Not turning at all...I try to spin the blade (engine off of course ) and it rotates only an inch or two and get stuck. So new fan?

Then I see that the belt below (in pic...YELLOW ARROWS) is upside down (teeth up) and seems to have slipped inside of the spools. It still works when engine running, but looks like it shouldn't..like it should slip or rub.

Can anyone shed some light on this? Maybe atleast tell me what this belt is for? Is it the AC compressor belt?

Thanks again...

KEN

Going from memory and going from right to left
the right most pulley is the steering pump,
the second and lower pulley is the alternator
The middle is your Driver/engine pulley
The left upper pully is the air pump (I think)
The left lower pulley is the AC Compressor
Hope that helps

Look to see if your fan is getting hung up on the air diverter hose. You can trace it from the filter in the middle of the radiator shroud. I didn't route mine properly back once and it also made a screetching noise.

the right fan will usually hit the suction line that goes to the AC compressor,
you can gently bend it towards the engine so it has about 1/2 in clearance from the back of the fan,

Also make sure the radiator top supports are tight and that they hold the radiator as far forward as possible.
the belt may have gotten loose on the AC compressor the lowest part on the passenger side of the engine.
BUT if you heard a clunk then your AC compressor may be seized or getting ready to fail,
you can test it with the engine off try turning the center section and see if it turns freely,

Usually if there are any issues with the belt or other noises when the compressor is working it indicates failure of the compressor ,
so if it doesnt work correctly do not use the compressor