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Q: AC blows warm while idling, cools during driving

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My car has gone around 130,000 miles. The issue is related to the AC, which works partially normal. While I drive and the engine revs up from 1700-2200 RPM, the AC works well. During idling however, the AC starts blowing warm air and it gets warmer and warmer the longer the car is not in motion. It cools the car again when I drive. The system has been charged. I also replaced the expansion valve. This didn't change anything however. How can I fix this? Thank you in advance.

Hello. There are a couple of things that could be causing your problem. The purpose of the high pressure hose is to increase and decrease AC pressure during different driving conditions. If the a/c isn’t blowing cold air when the car is idling, this is an indication that there may be a problem with the AC system high pressure hose. It is also possible that there is a problem with the AC compressor. I would recommend that you have a certified technician, like one from YourMechanic, inspect your car to determine why your AC is not working.

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