The job of an idle air control valve is to regulate the car’s idle based on how much air gets into the engine. This is done through the vehicle’s computer system and then sends the information to the components. If the idle air control valve is malfunctioning, it will cause the engine to idle rough, too low, too high, or irregular. Cleaning the idle air control valve on any car equipped with this valve, is fairly straightforward.
Part 1 of 2: Prepare for the job of cleaning the idle air control valve (IACV)
Step 1: Locate the IACV. It will be positioned on the intake manifold along the rear by the throttle body.
Step 2: Remove intake hose. You’ll have to take off the intake hose from the throttle body.
Part 2 of 2: Remove the IACV
Step 1: Disconnect the battery cable. Remove the cable that goes to the negative terminal on the battery.
Step 2: Remove the screws. Take off the two screws that hold the IACV in place.
- Tip: Some automakers use soft head screws for this part, so you’ll want to be careful not to strip them out. Use the correct size screwdriver for the best fit.
Step 3: Disconnect the electrical plug. You may have to squeeze on it to get it to loosen.
Step 4: Remove all other plugs from the IACV. You may need to use a screwdriver to loosen the clamp on one hose.
Step 5: Take the gasket out. Throw it away after verifying you have a correct replacement gasket.
Step 6: Spray carbon cleaner. Spray the cleaner in the IACV to remove dirt and grime.
Use a clean cloth to carefully wipe away anything that remains.
Repeat the process until no more dirt and grime come out of the IAC.
- Warning: Make sure to follow all safety precautions for using the carbon cleaner spray.
Step 7: Clean the IACV passages on intake and throttle body. Allow the gasket surface to dry before putting the new gasket on.
Step 8: Connect the hoses. Connect the last two hoses you removed and put the IACV in place.
Step 9: Attach the IACV. Attach it with the two bolts.
Reconnect the plugs and coolant hose. Reattach the negative battery terminal after everything else is in place..
Start the engine and check IAC operation.
- Tip: Don’t start the engine while the idle air control valve is out.
You should notice your engine runs more smoothly with a steady idle. If you continue to notice rough idling, talk to a trusted mechanic such as one from YourMechanic, to diagnose the problem. YourMechanic has a dedicated team of mobile mechanics who provide convenient service at your home or office.
This article originally appeared on YourMechanic.com as How to Clean an Idle Air Control Valve and was authored by Joyce Morse.