The Idle Air Control (IAC) valve regulates the amount of air bypassing the throttle plate, ensuring your engine maintains a steady idle. If the IAC valve fails, you may experience rough idling, stalling, or fluctuating RPMs. Replacing a faulty idle air control valve restores smooth idle performance and prevents stalling issues.

What is an idle air control valve replacement?

This service involves removing the faulty IAC valve and installing a new one. The mechanic will also inspect the throttle body and related components to ensure smooth airflow and proper idle control.

Why do you need an idle air control valve replacement?

A malfunctioning IAC valve disrupts the air–fuel mixture at idle, causing rough running and potential stalling. In some cases, it may prevent the car from starting or cause it to idle too high or too low, which affects drivability and fuel efficiency.

Common signs you need an idle air control valve replacement

• Rough or fluctuating idle RPM
• Engine stalling when idling or stopping
• Idle speed too high or too low
• Difficulty starting the engine
• Check Engine Light illuminated

What happens during an idle air control valve replacement?

A mechanic will:

1. Inspect the IAC valve and throttle body
2. Disconnect the battery and remove the faulty IAC valve
3. Clean the throttle body if carbon buildup is present
4. Install the new idle air control valve
5. Reconnect the wiring and battery
6. Start the engine and check for stable idle speed

How much does an idle air control valve replacement cost?

Idle air control valve replacement typically costs $250–$500, depending on the vehicle. If the throttle body also needs cleaning or replacement, costs may increase.

Is it unsafe to drive with a faulty idle air control valve?

Yes. A failing IAC valve can cause stalling, which is especially dangerous in traffic or at intersections. It should be replaced promptly to ensure safe and reliable vehicle operation.