What is the Idle Control Valve all about?
The Idle Control Valve is designed to control and maintain a consistent engine idle speed. The valve helps counter anything the driver may do to put extra load on the engine, such as turn on the air conditioning, sound systems, lights, etc. When the car is cold, the idle control valve helps the engine start.
Keep in mind:
The idle control valve usually goes bad because of excessive carbon buildup in the intake manifold.
How it's done:
- Scan the computer system in the car for codes.
- Check for any vacuum leaks.
- Check electrical connections.
- Remove and replace the idle air control valve if faulty.
- Clean carbon out of intake manifold ports.
- Clear Engine Check light.
It is a good idea to get an air induction service performed every 3 to 4 years. This will ensure that the carbon does not build up on the valve. When you are getting the idle control valve replaced, your mechanic should inspect the vacuum lines for leaks. If the vacuum is leaking, it will mimic the symptoms of a bad IAC valve.
What common symptoms indicate you may need to replace the Idle Control Valve?
- When the engine is idle, (car not moving), the engine may stall.
- Excessive racing noise from the engine.
- Engine may shut off if AC is turned on.
- Check Engine light is on.
How important is this service?
The idle control valve is responsible for maintaining a constant and consistent engine. It achieves this by ensuring that the idle speed is always constant. Many factors – such as a cold engine, the radio, or the air conditioning – effect the idling speed of the engine, so the idle control valve neutralizes these outside factors, and makes sure that the engine is consistently idling at a stable speed. When the idle control valve malfunctions, the idling speed is no longer regulated. This means that if you turn on the radio or the air conditioning, which requires power, your engine may stall. It also means that your vehicle may not be able to turn on.