Skip the auto shop - Our mechanics make house calls

Q: AC blows warm while idling, cools during driving

asked by on

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.

A: Hello. There are a couple of things that co...

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Ac not working and car overheating

The two cooling fans are controlled by a fan controller which is mounted in the center of the engine, above the radiator. The fan controller controls the fan speeds depending on the signals from the engine control module input. A...

Q: Neutral Safety Switch

Hi Chris, Your vehicle's neutral safety switch prevents the vehicle from starting when it is in any gear position other than park or neutral. If this has been removed, your car will not operate correctly as this is is a...

Q: Sometimes the cars blinker signal lights don't work and when that happens the air compressor quit blowing cold air

Hello. If your vehicle uses a transponder type key, it may be possible that a faulty key may cause issues, however, this is unlikely. It is more likely that your vehicle is experiencing some sort of electrical issue. Perhaps a...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...