Automotive Air Conditioning Information Forum

Ok the ambient air temp is 75. Its also overcast so Im not in direct sunlight. I have the engine at 1500-1600 rpms. I have the inside thermostat set at 60 and its blowing on high. The doors and windows are closed. My readings are: High side 250 low side 20 and the vent temp is 51. I then let it idle for a few minutes and high side was 220 low side 30 and vent temp was 55. I would think its a little low and should be colder since its only 75 outside. Oh and my gauges are new even though there probably from China like everything else.

Now its been idling for about 15 minutes and high side is 200 low side is 30 and the vent temp is 69.

Ambient temp today was 85.. So after running car for 10 minutes at 1500 rpms my low side read 30 and high side was at 200. Vent temp was in 60's. I added about 6 oz of freon. Ran it for a while and drove it a few miles. Dang vent temp was at 51 then at 65 then at 62. I just don't understand this thing. My gauges now read low side 35. High side 250.

Any more ideas? I had some other people suggest it was the blend door but I don't think so.

Does the low side line right at the firewall feel colder than what the vents do? The pressures are not far off.

I'll have to check that. My wife drove it for the last two days. It has been in the upper 80's. Yesterday she said the vent temp was in the upper 40's and lower 50's.

Yes temperature low at first then rises as the engine warms up really suggests that there is reheating. Check the evaporator outlet line like Jag987 said. Ideally, measure it with a thermocouple. The whole evaporator will be about that cold, so if it is a normal temperature of around 40, the air must be getting reheated after leaving the evaporator.