Auto Air Conditioning & Heater Repair: A/C problem on a 2002 Saturn L300, saturn l300, 2002 saturn l300

Question
I have a 2002 Saturn L300 that recently began blowing room temp air when the A/C is at max. I've done the basic checks to the system including checking for leaks, working compressor and clutch along with verifying I have enough R134 in the system. The low pressure side is reading 35-40 lbs when the system is running. When I touch the lines with, the high pressure side is warm but the low pressure side is either room temperture or a bit warmer. It's not the typical cold you get when the system is working properly.

I have also run the temp selector in the car and it works properly too. Any ideas on what may be the cause of the problem or other things I can check to locate the source of the problem? Thanks.

Answer
Jeff,
You said that your low side pressure is reading 35-40 psig witht he A/C on. Do you by any chance know what your high side pressure is reading? Also, how hot was it outside when you checked the pressure?
Assuming that your outside temperature is 85 degrees. Your low side pressure reading should be right around 54 psig.
I say this because from what information I gather from your question, your system is acting as the typical low charge system will. The low side line is cooler than the high side... that tells me your compressor is doing what it is supposed to. Does it cycle on and off at all? How about when you pull about 1500 rpms on the engine?
If you can send me your high side reading and your low side reading with the engine at 1500 rpms (this is where automotive compressors are designed to operate) as well as the temperature outside when you take them, I may be able to tell you more. The entire A/C system operates off of pressures, and you would be surprised what they are able to tell a good tech.
Also... I really don't want to send you looking somewhere else, until I can definately rule out a low charge because if it is charged correctly and acting as you state, my next stop is at the valves inside the compressor and that gets costly quickly.
I hope I helped a bit anyways, if you can please do a follow-up with the pressures and temperature and will be able to tell you more.
Thanks for your question and I await your response.