Hello All,
I am planning to buy 2000 A4 1.8TQ with some mileage on it. There is a whining noise coming from the engine compartment. One mechanic said it is Ac Belt Tensioner, and the other said the AC Compressor is going bad and needs to be replaced soon. AC is working properly and gets very cold. The noise is not very disturbing, and increases when I push the gas more.
What would the problem be? Any ideas are highly appreciated.
Thanks in advance

 

bump...

 

Sounds like the compressor is on the way out to me.

It should be fine until the air stops working.

Does it make the noise if the AC is not on?

 

The tensioner for the AC belt is VERY easy to loosen, remove and inspect. Surprised no one has done that for you yet.
Pull it off, test the bearing, and decide from there.

 

Use a silcone spary to lube the belt. If the noise disappears you have a belt issue. Otherwise you need a compressor.