AC issue ,1989 740 with 280,000 miles

Steve King · Post by **Steve King** » 19 Jul 2008, 07:16

A few years ago I converted to 134A due to a bad condensor. The AC system was working weel until yesterday. I checked the charge and it was at the proper level but the air comming out of the ducts was warm. I also did a visual check on the dryer and it was not "sweating" as normal when the AC is on. Also the compressor was running but I am getting noise out of it. So is it possible that the compressor is going bad (front bearing?) without leaking freon? And would this cause the problem or is it something in the heater/AC controls that maybe leave the heater valve open. Any suggestions would be appreciated. Thank you

Post by **billofdurham** » 19 Jul 2008, 12:24

Welcome to Matthew's Volvo Site.

Also the compressor was running but I am getting noise out of it

Is the compressor cycling as normal or is it running constantly?

If the front bearing is going bad the system would not necessarily leak freon. I don't think a bad bearing would cause the system to stop cooling completely unless it is so bad that the compressor is hardly turning.

Have you used the heater recently as this would be the only way for the heater valve to remain open? A simple check for the heater valve - there is an adjustment screw on the valve which, when turned 3/4 of a turn clockwise, will completely turn the valve off. If you still get warm air from the AC the valve is faulty. However, if you have not used the heater recently this would seem to be an unlikely cause.

Bill.

Steve King · Post by **Steve King** » 20 Jul 2008, 07:09

Thanks for the reply. I checked yesterday on the AC and it was in the "blue " zone at 30# for the low side freon. Compressor is running all of the time and is not recycling because the car does not cool down. When I measure the center duct temp I only get 68-70* reading. Outside temp is 95* with high hum. There is no leaks in the system but the compressor is noisey when you turn it on. When I did the 134a conversion I replaced the rec/drier and exp. valve. I had also replaced the condensoe(this was blown) and reoiled the compressor. I vacuumed down the system and it held 25" overnight. So all seemed well. System worked well for the last 2 years. Now it blows warm with a full charge. I am starting to think the compressor is not operating correctly. My next move is to order a remanufact. compressor and do the swap out. This is not a big job for a retired person (HAHA) but I just wanted to make sure I checked all of the potential areas. I'll have to check the heater valve but it is buried under the dash. Thanks