ive searched the fourm and ive found a few topics on this but none that have really answered this question, it all started when my factory ac compressor locked up on me, so i replaced it with a remained one and i flushed the system and changed the accumulator and orifice tube then went to work and used their ac machine to vacuum and charge it with oil and Refrigerant and shortly after that it began to whine, so in thinking there was an issue with the compressor i took it back and was able to get a brand new one then repeated the same steps all over again (note when a took the system apart after the remain compressor there was no metal or anything abnormal found in the system, but any ways shortly after i finished it it started to whine again just like the one before, and ive checked the belt tension, oil amount, and charge amount and all that is good a/c works prefectly fine its just i wana make sure nothing is wrong. i also found on the internet that some people say that replacement compressors will sometimes whine and im wondering if anyone has heard anything like that before??????