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Q: My car has been stalling out on me.

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My car has been stalling out on me at stoplights but if I hit the accelerator, it jumps back on. I got bad gas this summer around the same time my area got hit by a nor'easter and I did drive through some water but it wasn't bad at all and ever since, my car has been acting CRAZY (having to cold crank when I never had to do so before and sometimes wouldn't turn on).

About a month ago, I stopped on my way to AutoZone and they told me I have a bad battery, which at the time made sense with it shutting off.

Well for about a week (since I got my oil change), whenever I'm at a stoplight for a long time, it will just shut off on me. I figured out a trick about 3 days ago if I put the car in park and rev the engine lightly while waiting, it won't shut off.

I just don't know what to do and wanted to get advice before going to some mechanic and having them rip me off because I'm a young woman and obviously clueless about cars.

My car has 178000 miles.
My car's transmission is unknown to me.

A: This may be a sign of a failing idle air co...

This may be a sign of a failing idle air control valve. The idle air control valve is located on or near your intake manifold that monitors the air intake as it is mixed with fuel prior to being injected into the engine.

This valve is controlled by the vehicle’s computer which will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed.

However, when the engine RPM drops below the normal range of 800 RPM (for most cars), it is more than likely that you are dealing with an IAC valve problem. In cases where this valve is clogged or is failing, your vehicle will stall instead of slowing to an idle after the release of the throttle. I would recommend having a professional mechanic, such as one from YourMechanic, come to your home to replace your idle air control valve.

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