Blows hot air...again. I tried charging it. Then it seemed overcharged. Got gauges and showed pressure too high on high side and a little above normal on low side. Release some pressure from both sides. Started to cool again. But not COLD. Couple of weeks later, hot air again. Gauge showed low on low side (25psi). Added a can of 134a. Cooled agin, but not COLD. 3 days later, hot air again. Did some research and folks are saying might be the control valve/solenoid. Purchased the part but not seeing the steps to replace it. Do I need to drain the system? What is procedure for this? Any help is appreciated.

 

Sure sounds like a leak in conjunction with air in the system. Needs to be leak tested, repaired, evacuated and recharged properly.

 

unless you have equipment to evacuate the a/c system (which almost no one does since it costs several hundred dollars) you need to have a shop that does install the valve. the ac control valve in these cars fails often (3x in 10 years on my car).

 

Just had mine repaired. 2010 XC90 3.2. Bad compressor that pumped metal shavings throughout the system. Warranty covered half but they had to flush the whole system and replace some other parts.