How to Replace the Idle Air Control Valveby Johnathan CronkUpdated July 13, 2023
Items you will need
Idle air control valve
Throttle body cleaner
Whether you drive a Honda or Toyota, Chevrolet or Ford, engine idle problems are universal. The idle control valve in your vehicle is a very important component in maintaining the vehicle's regular idle speed. The idle air control valve, commonly referred to as the IAC valve, controls the idle speed by allowing air to bypass the throttle plate. When the valve becomes clogged, therefore blocking airflow, it can damage your vehicle’s engine and even lead to engine stalling. To avoid this, seek idle air control valve replacement immediately.
Determine Which Valve Is Malfunctioning
A bad IAC valve is indicated by an unusually high idle and check engine light. Contrastingly, problems with the PCV valve will cause a hissing or whistling sound and rough idling. Pay attention to the sound with your engine running to determine which valve is the problem.
Park the vehicle on level ground and allow it to cool for 20 minutes. This will ensure that all components are no longer hot to touch, preventing serious burns.
Open the hood of the vehicle and locate the idle air control valve. The valve is located toward the back of the intake manifold. The location may vary slightly based on the vehicle model, so you need to refer to the owner’s manual for the exact location.
Unplug the wiring harness from the IAC valve. There will be a small tab where the harness meets the valve. Depress the tab and pull the harness away from the valve to unplug it.
Use a socket wrench to loosen and remove the two bolts securing the IAC valve in place. The bolts are located on each side of the valve. Remove the valve from the vehicle by lifting it straight up.
Clean the valve mount with a rag and throttle body cleaner. This will ensure that the new valve sits properly and has a smooth connection.
Install the new IAC valve by placing it back onto the mount. Replace the two mounting bolts and tighten. Plug the wiring harness into the new valve. Close the hood of the vehicle.
Replacing the IAC valve at an auto repair shop lands anywhere between $120 and $500. If further car repair is required, such as a cracked gasket or a vacuum leak found, costs may increase by the hundreds. Check if your vehicle’s warranty will cover these expenses.
Things You'll Need
- Idle air control valve
- Socket wrench
- Throttle body cleaner
Johnathan Cronk is a freelance writer and began writing at the age of 18. Throughout his career he has specialized in sports, how-to and advice articles. He has also written sales pitches in the corporate setting since 2001. He studied business at Hudson Valley Community College before transferring to the State University of New York, Albany.