Started two days ago - I start my car as I'm going out for lunch (electric start) and when I get out there its makeing the god awful sound. The noise sounds like a bearing that has busted apart and now the parts are rattleing around inside of somthing. Its comming from the lower front of the engine. Now I get in my car and the A/C is kickin full (still cold) so I turn the fan down to zero and off. Now the sound goes away. So I'm thinking maybe its gone away by itself, so when I get home I turn the A/C back on full and step out of the car - the noise comes back - like I said above it comming fromt the bottom of the front of the engine compartment. Any Idea's

 

COnpressor could be shot or secondary Air Pump

 

maybe?

found this on ECS

OE A/C Compressor Belt Tensioner/Roller Assembly
Tensioner roller assembly for the A/C Compressor belt that should be replaced if the bearing is noisy. This is Ruville made in Germany brand

 

Check your dv vac line. It runs right next to the AC fan. I had the EXACT noise/situation you are describing 3 days ago. i had replaced my DV vac line and there was too much slack by the AC fan and the fan was hitting the vac line and making the noise you describe when i turn the AC on.