How To Clean Idle Air Control Valve: The 5 Easy Steps to Follow

Do you know an air control valve is usually a place that accumulates a high density of carbon which will prevent the flow of fuel and cause your engine to work no-effective? So cleaning this small valve periodically is an important step to prevent a rough ride and save your money. In this article, we’re going to show you right quick how to clean idle air control valve on your fuel-injected vehicle. Some vehicles they’re built a little differently but the process is generally the same. 

What Is An IAC Valve?

what does a idle air control valve do
What does an idle air control valve do in your vehicle? (Photo:

The idle air valve is a part commonly installed in fuel injection vehicles with the function of enabling your engine to idle effectively rather than stalling out when your car stops. Often an IAC is attached to the engine throttle. And its purpose is to regulate the airflow in your engine and help to create smoother idling.

The IAC controls the amount of air entering the engine cyclically. This process is accomplished by regulating airflow through a bypass circuit around the throttle to increase or decrease idle speed. Increasing the volume of air flowing through the bypass circuit around the throttle valve increases the idling speed. 

When talking about the engine idling speed is the speed in revolutions of the engine when the driver’s foot is not on the accelerator pedal. While the throttle is closed, the main intake manifold of the engine is closed. So a bypass is required to avoid stalling the engine.

We can’t deny that an IAC valve is a very important component in a car’s engine having an issue with the IAC valve can lead to big problems with your engine. To keep this valve always working in a good condition, idle air control valve cleaning is a key factor.

How To Clean Idle Air Control Valve? 

Over time, the IAC valve will build up carbon that causes this valve to be clogged or dirty and the consequence is more or less airflow to enter your engine. At that time, you will have 2 options: replace an idle air control valve or clean it, depending on the condition of this valve you will make the right decision. However, do you know that an IAC valve is one of the most pricey components used in your engine system?

So you can absolutely save a big amount of money by buying a new valve by cleaning the existing one. If you want to make this process by yourself, it’s important that you check your car owner’s manual when you intend to clean the IAC valve. You will not want to cause any further damage and the manual should provide you with accurate information on how to correctly clean the valve.

However, if you can’t find the relevant information, here’s a step-by-step guide on how you should work with most of the vehicle when cleaning an IAC valve. But before starting a process, you need to make sure the engine is off and completely cooled down or you can disconnect the negative battery cable:

Step 1: Locate the position of the idle air control valve

idle air control valve cleaning
Idle air control valve cleaning is not a simple process (Photo:

It will be a challenging task for identifying the exact position of an IAC valve If it’s the first time you clean this valve. The idle air control valve is usually near the throttle position sensor connected somewhere around the throttle body. For beginners, it can be a little tricky, you can start by locating the air filter box then you will follow the duct which will pass through the mass flow sensor and further into the engine. Here, you can find the throttle body and also the idle air valve. Make sure you find the right IAC valve or you could destroy the entire engine by finding the wrong valve.

Step 2: Detach the air intake hose and filter box

The next step, using a screwdriver to loosen and remove the screws used to fix the filter box. In this step, you also need to disconnect the power line associated with the MAF sensor in case your vehicle has any problems! However, be careful about the part of the plastic tang that fixes the harness.

Don’t break it because the wire leading to the harness will come apart. And that will cost you a lot more time to handle and it will be more complicated than cleaning the air valve. The harness is kept from shaking with the help of that plastic tang. Our advice: Make sure you don’t mess up all the wiring and hoses. After removing the air intake, you can reach the idle air valve. If you don’t still locate it, you can refer to the vehicle manual.

Step 3: Remove all clamps that are connected to the IACV

Detach all the clamps that are holding an IAC valve. Remove the old gasket (no need to scrape it because it is a metal gasket). In this step, you will find the throttle body and your task is to place a small hole or passage inside it. 

Step 4: Clean the idle air control valve

Using a brush to remove the dirt on the valve surface. When cleaning the inside of the valve, you will need specialized detergents like carburetor cleaners. Wipe or spray the inside of the triangular face to clean any deposits to ensure no carbon residue remains. Spray a carburetor cleaner onto the pointed end of the valve. Try not to get any of the cleaners into the valve’s housing as this may cause damage.

Continue to spray the cleaners until you see all of the carbon or debris has come away. Remember, not all carbon cleaners may be suitable for all vehicles and components. You should only use the products if you’re confident that they won’t do any harm. After removing completely carbon, the air valve needs to be reassembled in the detached position and the harness attached to its original position.

Step 5: Test by starting your car

The best way to check your engine after finishing the cleaning process is to let your car start up and then spend a few minutes idling. Once everything is reinstalled correctly, you can now start your car and listen to how it idles. If the dirty was an issue, you should now notice the improvement in the sound and your car will be running smoothly. At that time, it means that your mission is successful otherwise you will have to do the above steps one more time. After cleaning and still not effective, it is time to replace the idle valve. You should buy replacement parts from reputable stores to avoid buying fake goods, or poor-quality goods.

>> Read more: Bad Throttle Position Sensor Symptoms & How To Fix


Here’re some other frequently asked questions about an IAC:

How to test an IAC valve? 

There are many ways to help you to test the idle air control valve like starting your car, testing an IAC with a multimeter, OBD scanner, or voltage test light. We think the easy method you can use to test the IACV is to turn your car on and listen to the idling engine. A fully functioning valve will sound even and smooth, and you will not notice any “bursts” in sound or speed. In addition, you can use a multimeter, but this method will be a little complicated.

You should set the multimeter unit to be Ohms, after that, place the red lead on one terminal of the IAC valve, and put the black one on the other terminal. If your IAC valve works correctly, the resistance will range from 7 to 25 Ohms, depending on your vehicle. Another number is a warning sign of a bad IAC valve. To know more about the process to test your IAC valve, you can read another article from our site:

>> Related post: 6 Bad Idle Air Control Valve Symptoms & How To Troubleshoot

What are the symptoms of bad idle air control valve?

It’s important to be aware of the idle air control valve symptoms when it’s going bad. These include stalling, poor acceleration, increased RPM, or a warning check engine light on your dashboard. If you notice any of these signs, you need to test or check your IAC valve immediately for faults. This is important to know about the recommended idle range to give the exact diagnosis because this date will depend on your type of engine. 

symptoms of bad idle air control valve
Symptoms of bad idle air control valve will include: stalling, poor acceleration, increased RPM (Photo:

What happens If you unplug the IAC valve?

You can absolutely unplug the IAC valve and it should not cause any damage. If you disconnect it while the engine is idling. However, the IAC valve plays an important role in keeping the airflow in combustion while idling. So there’s a risk when removing this valve causing some adverse effects. 

Final Thoughts

An IAC valve may not be performing correctly because it is dirty and is in need of some cleaning maintenance. During combustion, carbon and debris can settle on the IAC valve and this can build up over time. When contamination builds up inside the idle air control valve, at that time the IAC may become faulty and not work as it should. Cleaning away any built-up debris or contamination can help you to reset the IACV back to working order.

In this article, we’ve explained how to clean the IAC valve by removing it. If you want to learn how to clean idle air control valve without removing it, there will be several guides available online that you can refer to. Whilst the idle air control valve is designed to last your car’s entire lifetime, sometimes damage and debris could cause issues. Cleaning this valve is a very useful way to keep your car working effectively.