I had the same problem, so I went to the dealer to look at their parts book. The dealer told me that many of the 320i had dealer installed a/c , not factory installed a/c. The dealer didn't have any parts or diagrams of my compressor. So I was screwed, and I had no a/c, which sucks in Texas. I don't know where you can get info on the compressor, but someone on this board may have torn one apart by now. good luck.