i had a horrible noise the other day and decided to investigate. i removed the serpentine belt and rotated the pulleys to see which felt bad or made noise low and behold the ac compresser pulley is grinding and making aweful noise during idle. i could feel it when hand turning so i sprayed some grease in there to help relive the noise till i could decide what it was also not a good idea since it seems to burning off and smeels really bad. took it to local mechanic know for years and says it sounds like just the clutch in it is bad. how easy is it to replace the whole thing compressor and clutch my self is this a diy?