I just installed a new a/c compressor on my 318. I'm getting a knocking sound whenever the compressor is on. It doesn't happen when its off. Anyone have any idea? Thanks
It's hard to tell if your new compressor has a problem with out actually hearing it. RV- 2's are noisier than newer compressors. They make their own unique sounds when moving refrigerant around.
As far as I know only rebuilt RV-2's are available these days and most of the chain store rebuilts are Four Season units. Four Seasons are not known for the best rebuilt compressors so you may indeed have a bad one. I'm not sure were you can find a quality rebuilt RV-2 these days.
Also, the installer is responsible for insuring the right quantity and type of oil is used. These compressors were originally used with R-12 refrigerant which used 525 A/C mineral oil. Today's more common R-134A would use PAG or Ester oil. Since the rebuilder has no idea which refrigerant will be used They often ship the compressors dry or with some type of shipping oil which must be drained out and the proper oil put in.
Belt tension is critical or the belts slap around and make strange noises. I've never heard of a break in period for these compressors.
