My 1987 BMW 325e has the original Denso compressor. The summer of 2003, shortly after I bought the car, I had the system evacuated and recharged with R-12 since it wasn't working so great, and the identity of the refrigerant was questionable. The A/C has been working fabulously since.
Yesterday, I was driving and decided to turn the A/C on (even though it was only about 75 degrees out) since I hadn't used the A/C in about a week and half - you know, just to keep the system working properly. To my surprise, the air did not get cold. The last time I had used the A/C, everything was working great. I stopped the car and checked out the situation under the hood. I was surprised to see that the compressor was engaging, but the low pressure line was not getting cool at all - it was at the underhood ambient temperature. No bubbles were visible in the sight glass on the receiver/dryer. Since the compressor is still engaging, I surmised that the system is probably not low on freon (unless, of course, the low pressure switch is bad), and it seems that this would be a rather abrupt loss of a significant amount of freon since it was working great about a week and a half ago. The A/C has not been getting warmer like it has a slow freon leak. None of the underhood fittings or hoses displayed any evidence of a leak, either.
At this point, I am guessing that either the compressor is no longer working properly (but it hasn't frozen and doesn't make any noise when engaged) or the expansion valve is possibly bad??? Any advice on how to approach my problem would be greatly appreciated, since the local shops want to evacuate the system and recharge it to diagnose the system at the tune of over $300. Then, if something like the compressor or expansion valve needs to be replaced, it'll require another evacuation and charge after whatever needs to be replaced is replaced.
Yesterday, I was driving and decided to turn the A/C on (even though it was only about 75 degrees out) since I hadn't used the A/C in about a week and half - you know, just to keep the system working properly. To my surprise, the air did not get cold. The last time I had used the A/C, everything was working great. I stopped the car and checked out the situation under the hood. I was surprised to see that the compressor was engaging, but the low pressure line was not getting cool at all - it was at the underhood ambient temperature. No bubbles were visible in the sight glass on the receiver/dryer. Since the compressor is still engaging, I surmised that the system is probably not low on freon (unless, of course, the low pressure switch is bad), and it seems that this would be a rather abrupt loss of a significant amount of freon since it was working great about a week and a half ago. The A/C has not been getting warmer like it has a slow freon leak. None of the underhood fittings or hoses displayed any evidence of a leak, either.
At this point, I am guessing that either the compressor is no longer working properly (but it hasn't frozen and doesn't make any noise when engaged) or the expansion valve is possibly bad??? Any advice on how to approach my problem would be greatly appreciated, since the local shops want to evacuate the system and recharge it to diagnose the system at the tune of over $300. Then, if something like the compressor or expansion valve needs to be replaced, it'll require another evacuation and charge after whatever needs to be replaced is replaced.