I always feel hot-blowing air surrounding my Volvo 940 after driving for over 1 hour, and the cooling fan (just newly replaced) has to run about 15-30 sec after engine is turned off. I was told the exhausted air could not go out due to blocked catalytic converter and had it replaced with new one before but the problem remains.

Recently my A/C fails to cool after car runs for about 1 or 2 hours. (I just had a new A/C compressor installed, and full service on A/C system.) If I stop the car, I can feel the hot air all over my car; from underhood and below the car. I knew the Volve car has a mechanism (computer control?) that will disable A/C when engine pressure gets high or over-heat. I worry if something major is wrong with my 940 that can cause fire or personal injury if I do a long-distance drive. There is nothing wrong shown on the instrument panel.

Recently I have problems with the followings and all replaced with new parts:
new water pump (for < 500 mileage)
new air compressor (for < 500 mileage)
new cooling fan (for < 1000 mileage)
new catalytic converter (for about 10000 mileage)
(I have 100K mileage on my 940)

Could it bacause of exhaust system, engine, cooling system, sensors or faulty valves? Any comments or suggestions are highly appreciated.

MT