I had the chance to carpool with a friend and I learned something new in the process. When he started the car, I noticed that the engine sounded as if the gas pedal was depressed. I looked at the RPM and saw that the idling was at 2000 RPM.
I found that really unusual so I did some research. I found out that one of the reasons for high idling is a problem with the idle air control valve.
More...
in 10 Easy Steps
The idle air control valve is one of the motors in a fuel-injected vehicle. The idle air control valve, or idle air control actuator, regulates the idling RPM of the engine, which in turn is controlled by the engine’s computer.
I would like to share with you some tips on how to clean idle air control valve should you be faced with the same situation.
How Does the Idle Air Control Valve Work?
But before we go through the steps, let’s discuss what the idle air control valve is and how it works. When you start your car, the idle air control valve bypasses the air so that the engine still gets air when idle.
You will notice that in newer car models, you don’t need to step on the gas pedal to start up the engine.
This is made possible by the idle air control valve. Another name for the idle air control valve is the idle air bypass valve because its job is to bypass air so that the engine starts up.
In some cases, the valve becomes jammed and needs cleaning. This article will educate you on how to clean the idle air control valve.
How to Determine Issues With the Idle Air Control Valve
To determine if there is a problem with the idle air control valve, here are some signs you need to watch out for:
- Check the RPM - The idle RPM should not be above 1000. On your dashboard, the needle should not be above the number 1 nor should it fall to low. Ideally, the needle should stay at number 1, or idle at 1000 RPM.
- Engine stalls - When the idle RPM is too low, the engine stalls or suddenly stops.
- Check the engine light - The Engine Control Unit (ECU) identifies problems with the engine. So when the engine light comes on upon idling, then there is an issue.
Common Problems With the Idle Air Control Valve
When your car is not idling correctly, there could be an issue with the idle air control valve, such as:
- Vacuum leak - The vacuum lines in the engine bay could be damaged, cracked, or worn out. Spray soap and water mixture on the vacuum lines. If there are air bubbles, then there is a leak.
- Servomotor needs replacement - The servomotor regulates angular or linear position, velocity, and acceleration. This is associated with the idle air control valve.
- Partially or completely jammed - This happens when the valve is blocked with dirt, dust, or oil.
Steps on How to Clean the Idle Air Control Valve
Now, let’s get started and learn the steps on how to clean the idle air control valve so your car idles normally and fuel efficiency is maintained.
Word of Caution
The steps below should be done by a skilled professional. If you don’t have any experience with these, get a mechanic or car expert to do them for you. It will save you from harm and avoid damage to your vehicle.
Here is a three-minute video to help you get started.
What You Need
Carbon cleaner is used for removing and liquefying engine deposits and other contaminants. It also helps avoid corrosion and fuel line freeze-ups.
We recommend that you try Sea Foam SF-16 Motor Treatment. Be careful when handling carbon cleaner, read the safety instructions before proceeding.
Other Stuffs
- Clean cotton cloth or microfiber cloth - for wiping off excess moisture
- New gasket - to replace the existing one and safeguard the valve against leaks. You can purchase a fuel injection idle air control valve gasket by clicking here.
- Screwdriver and wrench - to remove screws and bolts from tubings or hoses
- Surgical face mask - to avoid inhaling toxic fumes
- Work or household gloves - to protect your hands from heat and harmful chemicals
What You Need to Do
Remember to put on your face mask and protective gloves before you start working. This helps prevent any minor injury and from inhaling toxic fumes.
- Step 1: Find the idle air control valve (IACV). It is located at the rear of the intake manifold near the throttle.
- Step 2: Loosen the screws and detach the air intake hose from the throttle body.
- Step 3: Remove the battery cable that is attached to the negative terminal.
- Step 4: Use the correct screwdriver size to remove the screws that hold the idle air control valve.
- Step 5: Softly squeeze to disconnect the electrical plug.
- Step 6: Use a screwdriver to remove other screws and loosen the clamps on other plugs that are connected to the IACV.
- Step 7: Remove the gasket, make sure you remember where and how it is placed.
- Step 8: Attach the nozzle to the carbon cleaner if it is not attached. Spray it directly onto the idle air control valve. Wipe off with a clean cloth. Repeat the process until all the dirt and grime are gone.
- Step 9: Use a clean cloth to wipe off any residue from the IACV, intake manifold, and throttle. Make sure the surface of the gasket is dry before you attach the new one.
- Step 10: Reattach everything that you remove starting from the two hoses you removed.
Notice
When using the carbon cleaner for step 8, be careful that you don’t inhale it and it does not come in contact with your skin.
When reattaching things for step 10, don't forget to do it step by step: Reattach the IACV and securely connect the two bolts first, then connect the coolant hose and the plugs. The negative battery terminal should be the last thing you reconnect.
After you have wiped off all residue and reconnected all the plugs, hoses, and screws, you can start your engine and check idling. Your engine idling should run more smoothly and more steadily now.
Conclusion

via Youtube Channel 'corgLLC'
Now that you have learned how to clean the idle air control valve, why don’t you share this article with your friends and other car enthusiasts?
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I can´t see where is my IAC valve on my BMW x5 e53 4.4l 2001, can you send me some pictures please?
Thanks in advance
Hello,
I have a 1999 Rx300. I had to replace idle control valve. I removed the valve and replaced it with a IACV from eBay. I found that the RPMS were higher when the car was warming up. The car at idle was hovering around 1000. Too high…. I also noticed my coolant level dropped I replenished it twice. I am wondering if the the valve is substandard to a Lexus valve and if there is a leak in the gasket ?
Hi David, I am very impress to read your article But i have problem in my car and three mechanic couldn’t fix it and cost me $1200. I am very badly broken i have to work two week to make money.Please help and diagnose my car problem i will appreciate. I have Camry 99 LE,2.2 auto. when i drove on highway it is fine but when i slow down on traffic light it stall and shutdown and than I have restart. Three mechanic did job on this was, they clean throttle body,clean IDE, change fuel pump, fuel filler,EGR, Engine flushing and put the speed high but nothing could solve the problem.Yesterday i repaired EGR and at night I drove to home and when i put it in parking RPM goes immediately high and drop after one minute later and car shut down.I am so upset and don’t know what to do where to go and trust who.Please advise. Thanks