Skip the auto shop - Our mechanics make house calls

Q: When i have my car running with my heat or ac on my car hesitates like it wants to stop when i'm stopped at a light.

asked by on

When I have my car running with my heat or ac on my car hesitates like it wants to stop when I'm stopped at a light. Sometimes it does cuts off when I'm waiting at a light, then I have to put it in park then start it back up. What will it be?

My car has 192000 miles.
My car has an automatic transmission.

A: As you may know, your car’s AC system when ...

As you may know, your car’s AC system when working properly puts an extra load on the engine at all times when it is running. When this happens, your car’s computer makes adjustments to compensate for this extra load on the engine. There is a component in your engine’s intake system called an idle air control valve that helps to control air intake as it is mixed with fuel during idle or low speeds. When this is dirty or not working properly (especially under load from additional power required for the AC), tis may cause incorrect adjustments to be made to the fuel mixture causing the hesitation you describe. I would recommend having an expert from YourMechanic come to your home to take a look at your car to properly diagnose and repair your idle air control valve.

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: My car has to be cranked two or three times before it starts. New spark plugs did not help.

Usually when it takes multiple times to ignite, it's due to an obstruction of fuel or difficulty mixing the fuel / air correctly. I would have your mechanic inspect the mass air flow sensor, the EGR valve and the fuel...

Q: I was driving and all of a sudden my car made a loud horrible screeching sound and it continues as long as the engine is running

The noise sounds like you have a belt pulley that is seized. You will need to either start the vehicle and look for the pulley to component that is not turning or will need to remove the serpentine belt and...

Q: Honda N WGN 660 5cc japanese frequent limp home mode

Hello, thanks for writing in about your Honda N WGN. A likely possibility related to the misfiring may be that the car's computer may have tried to recalibrate the fuel supply as a result of the faulty throttle control relay...

Related articles

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...
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...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...