Skip the auto shop - Our mechanics make house calls

Q: A/C

asked by on

My a/c will blow cold while driving but at an idle it blows warm any ideas what could be going on? Both fans working when i looked while the car was running and a/c on.. Freon tested good as well

My car has 107000 miles.
My car has an automatic transmission.

A: First check to make sure the front of the c...

First check to make sure the front of the condenser is clean and free of bugs or debris. Try and spray it with a lower pressure hose or car wash hose from farther away and clean it out as best as you can to see if it helps. When an A/C system works well on highway, but gets hot at stops, this is due to the system being low on Freon, blocked condenser fins, fans not working or the compressor is not working good at idle. If cleaning the fins do not work, then have a mechanic check the pressures to see why it is blowing warm at idle.

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・Save up to 30%

Get a quote

What others are asking

Q: Grinding/Scrapping noise

This may be potentially related to the brake rotors which can accumulate a slight rust film on them even when sitting just overnight. When you begin to drive in the morning and they are cold, the scraping sound you may...

Q: Mice can get into the ventilation

Rodents can become a serious problem for almost any vehicle. If they don’t find their way into the HVAC system, they will often chew on wires, which can cause serious problems with vehicle operations. In this case, cutting and installing...

Q: A.c. not turning on at all

The blower control blend door actuator on the evaporator case may be bad. Have the blend door actuator removed to see if the blend door can be turned by hand. Sometimes, the actuator breaks and other times, the blend door...

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...
What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...