Nissan Repair: Nissan Altima A/C stops working with high heat, nissan altima, expansion valve

Question
Hi,

I have a 1997 Nissan Altima GLX with a standard A/C (not automatic). Whenever it is really hot, yesterday it was 93, my A/C stops working after about 10 min and only blows out warm air. Also, when the A/C stops working my car (engine) chokes a bit. I recently checked my A/C pressure with a refill kit and it seems to have to appropriate pressure eg. 50-55 psi with an ambient temperature around 85. Could you please let me know what the problem could be? Thanks!

Answer
Matt,

I would like to know what the high side is reading.  But, the low side seems to be correct as you indicate.  I would be thinking it was the expansion valve but the pressures you indicate seems to be normal.  Check to see if the compressor is binding as you might need to replace the compressor.  When you say it lugs the engine down that would be the compressor going out.  But, if the compressor is ok be sure to check the high side pressures and if they are really high or low you have a bad expansion valve.