4 SYMPTOMS OF A BAD IDLE AIR CONTROL VALVE

purpose

The purpose of the idle air control valve is to regulate the amount of air coming into the engine while stationary to ensure a smooth idle. Your car might not have an idle air control valve. Some newer cars have an electronic throttle body that’s controlled by the ECM (engine control module) to open up and allow airflow to ensure a smooth idle. An idle air control valve can go bad in 3 different ways: stuck-open, stuck-closed, or clogged.

location

The location of the idle air control valve will be near the throttle as shown in the video below.

symptoms

engine light

The first symptom of a bad idle air control valve is having an engine light on. Here are some codes that can show up:

• P0505

• P0506

• P0507

• P0508

• P0509

Ensure you can access your car's diagnostic codes by acquiring an OBD2 scanner here.

IDLE TOO HIGH/TOO LOW

The second symptom you might be experiencing with your car is noticing your idle is too high or too low. If the idle air control valve is stuck open, it will increase the air going into the engine, which will increase your RPM, usually above 1000. If the idle air control valve is stuck closed or clogged, it will restrict air from coming into the engine, which will cause your RPM to drop below 600. An average idle RPM range should be between 600 and 1000.

engine stall during idle

The third symptom of a faulty idle air control valve is the engine stalling during idle. If the idle air control valve is closed or clogged to the point where not enough air is coming into the engine to keep it running, it will result in an engine stall.

crank but no start

The fourth symptom you could be experiencing is a crank but no start. The starter could be turning the engine, ignition coil, spark plugs, fuel injectors, and sensors could be running perfectly but if there isn’t enough air coming into the engine, there will never be consistent combustion, preventing your car from starting.

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If you suspect a clogged idle air control valve, try cleaning it first before replacing it. I recommend buying this cleaning chemical.

If you concluded that your idle air control valve needs to be replaced and you want to do it yourself, I would recommend getting a repair manual here. You can use code “AD10VA” for 15% off one-year subscriptions for any US Order.

You can also buy a new idle air control valve here.

Check out my YouTube video!

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