Idle Control Valve Buyer's Guide
- Older vehicles rely on the idle control valve to ensure smooth engine idling and prevent stalling. The valve makes it possible for the car to immediately roll out once the driver disengages the clutch.
- The idle control valve manages the engine’s revolutions per minute (RPM) during idle moments when the vehicle doesn’t move. It controls the flow of air around the throttle plate.
- A replacement can cost anywhere between $4 and $923.
- Check the compatibility of the replacement idle control valve with your vehicle. Avoid reusing old valves as they wear out faster than new parts.
Your car’s engine needs the right amount of air to keep its engine running smoothly while it’s sitting still. In vehicles built during the preceding decade, the electronic throttle actuator controls the air supply for idle speeds.
However, many people own vehicles designed before the onset of throttle actuators. These older vehicles rely on the idle control valve to ensure smooth engine idling and prevent stalling.
What Is the Idle Control Valve?
The idle control valve oversees the idle speed of the engine. Also called the idle air control valve - IAC valve for short -, the mechanism regulates the air that goes around the throttle plate. It usually connects to the throttle body beside the intake manifold.
What Does the Idle Control Valve Do?
In cooperation with other components, the idle control valve manages the engine’s revolutions per minute (RPM) during idle moments when the vehicle doesn’t move. By maintaining a steady idle speed, the valve makes it possible for the car to immediately roll out once the driver disengages the clutch.
To activate the valve, the engine control module (ECM) transmits a signal. The internal motor sends air around the throttle plate at the desired speed. The air leaves the throttle body and travels to the engine.
The ECM keeps track of various factors like the engine’s current load and temperature. Based on data from the coolant temperature sensor, throttle position sensor, and other monitoring devices, the computer adjusts the valve to raise or lower the idle speed as needed.
How Much Does an Idle Control Valve Cost?
A replacement idle control valve can cost anywhere between $4 and $923. You can get individual valves, sets of 2 valves, and kits with other parts like throttle position sensors.
Selecting the Best Idle Control Valve
Be it a replacement for a broken idle control valve or a general upgrade, you want only the best for your car. The following tips can help you narrow down your options.
Ever made the mistake of buying an expensive replacement part and finding out that it didn’t fit in your car? Always take the time to check if your intended idle control valve enjoys compatibility with your vehicle.
If you’re shopping online and the website features a filter bar, you can save yourself some trouble. By entering the year, make, and model of your vehicle in the filter bar, you can quickly browse the shop’s offerings for a replacement valve guaranteed to fit your car.
New parts vs. used parts
You may find it tempting to swap a bad idle control valve for a working but used part. Brand new valves don’t always come cheap, and the high-end ones can cost hundreds of dollars.
However, used valves break down more often than new parts. The higher chance of failure comes from the carbon that built up on them during earlier use.
How to Install an Idle Control Valve
When defect and damage strike, replacement should be an immediate option to maintain the ride's smooth idling.
Required skill level: Novice
Tools you'll need:
1. Scan tool
2. Engine oil
3. Shop rags
Locate the idle control valve in your car
Pop the hood and access the idle control valve. It is usually at the top-center of the engine, attached to the throttle. In some models, like the Crown Vic and Grand Marquis, the ICV can be accessed at the back of the air intake section, where one would expect a carburetor. It is only a small device, almost the size of your hand.
Disconnect the valve
Pull out the electrical connector from the ICV. You will also see two bolts and an exhaust hose attached to the valve. With a socket wrench, remove the bolts first, followed by the gasket. Once these have been detached, unplug the exhaust hose by twisting the ICV a little.
Clean the sealing surface
Use the shop rag to clean the sealing surface and the throttle body assembly. A clean area is also necessary in the upkeep of the ICV.
Install the new ICV
After cleaning the mounting surfaces, assemble the new idle control valve. Don't forget to apply some clean engine oil to the gasket prior to the installation. Set up the ICV in almost the same manner as the old valve was detached. Tighten the bolts and plug the electrical wirings. To check if the installation was successful, conduct a test drive, but don't forget to erase the codes and commands on the scan tool first. Happy idling!