My AC is not blowing any cold air, just warm or hot air. There is a significant noise coming from the engine from the area of the belt and pulleys in front of the engine. What does this mean?
I have an Audi A4 2006 2.0 T

 

Guessing the compressor failed or the bearing in the pulley is going bad (or gone bad). I would think noise would indicate bearing issue. Either way it needs to be checked. If the compressor freezes it will throw the belt off.