I too had this problem on my 1993 Mazda 626 4cyl Automatic
I started hearing a rattling sound while the engine was at idle(from the compressor) and it would disappear when rpm increased.
Slowly the cooling decreased and finally ended. I went to a mechanic and he came to a conclusion that the compressor (is damaged and) needs to be replaced since he was not able to recharge the comp. With refrigerant as the pressure gauge showed 0 psi all the time.
I figured out myself that this was not the compressors fault but the wire connecting to the relays was disconnected. Cheers to 626 workshop manual.
After two months I tried doing it myself. Got a R12 to R134a adapter from walmart and 18 oz of r134a refrigerant with oil, 2 bottles of 13oz r134a.
Filled in the refrigerant myself drove couple of times and my ac started working. I dont hear that rattle anymore but who knows it might start again as it did before.
This might not be the best solution or maybe the right solution to it but it worked for me. I was about to spend $500 for an AC compressor Replacement. Thank God I saved $450.
SPONSORED LINKS
Sunday, August 17th, 2008 AT 12:14 PM