My car (1998 V70 T5 auto w/ electronic climate control) has always blown ICE COLD air since I bought it last March. A couple of months ago the air will suddenly blow warm air. I turn the A/C off for a few minutes then back on and it will blow cold again for a few minutes. I thought it might be the clutch on the compressor so I tried the bread clip trick. Not a chance, the clutch is so tight that the bread clip would never fit. I noticed that this problem only occurs when it is EXTREMELY HOT outside, like 95 degrees F. and above. In the morning when it's cooler it blows ice cold. I took it to an A/C mechanic whom I trust one morning. It was about 80 degrees that morning so the A/C was blowing very cold. The mechanic said that he really needed to see it when it was blowing warm air. He did check it out and said that it had plenty of refrigerant and no signs of leaks any where.

As part of my routine maintenance I was doing a complete coolant flush. The old coolant didn't look that great. Even though the previous owner said that they flushed the coolant when they changed the thermostat and engine coolant sensor. I took the car to the car wash and pressure washed the condenser to get out all of the dead bugs and dirt. While doing this I noticed that my engine seemed very hot. The upper radiator hose was too hot to even touch. My temperature gauge needle is always at a 90 degree angle while driving. Here in South Texas we daily get temperatures well above 100 degrees.

I'm wondering if the previous owner could have put in a thermostat for normally aspirated engine instead of one for a turbo engine? N/A engine use a 92 degree Celsius (197.6F) while a turbo engine uses a 87 degree Celsius (188.6F). Also Auto-Zone shows no difference between turbo and non-turbo and recommend a 192 degree thermostat. Could this be enough of a difference to affect my A/C? Could this also make my engine seem like it running hot? The engine running hot could be me being paranoid I guess.

After pressure washing the condenser and doing a coolant flush. My A/C still cuts off but not as often. I have yet to take it on a long drive though. As soon as my 8 inch T-40 bit comes in I'll change the thermostat.

Any ideals, tips or advice would be greatly appreciated.

Thanks.