Hi all, i got myself a big headache probably because i try to save money and fix things by myself haha. I've bought my B8.5 few months ago and i did notice right away that there is some grinding/bad bearing noise coming from the AC compressor area and AC wasn't working (system had pressure and was filled correctly). Noise was quite annoying and I didn't wanted to spend money on fixing the issue back then, so i came up with idea to get myself shorter serpentine belt and install it avoiding ac compressor pulley. So i did that and it worked perfectly and there was no more grinding noise yeayy!

So that should confirm me 100% that this noise was coming from compressor isn't it? But now I'm not sure as today i have installed brand new compressor put back correct length belt and the noise is back!! 

Compressor was filled with oil and recharged correctly. So could it be that new compressor is faulty same way as the old one? Or there is something else i could have missed?

Noise does go away completely with higher revs, and gets better on idle when engine warms up.

 

Forgot to mention that new AC compressor works perfectly fine minus the noise

Is there a belt tensioner that you bypassed with the short belt?

No i haven't, i did replaced belt tensioner too