How to Clean an Idle Air Control Valve in a Honda Accord

Last Updated: August 10, 2021 References

An idle air control valve (IACV) adjusts a car's idle depending on the amount of air that is entering the engine. The car's computer takes readings of idle control adjustments and regulates the car's rpm accordingly. Therefore, if the idle air control valve is not functioning properly, you will notice that your car is revving or idling irregularly. A high, fluctuating or erratic idle, or an idle that stalls out sporadically, is a sign that you may need to clean the idle air control valve. You do not need to be a mechanic in order to clean the IACV, but you will need some familiarity with the car parts under your hood. If you drive a Honda accord and your idle control is acting up, you will find that the IACV is readily accessible for ease of maintenance. Follow these directions for how to clean a Honda idle air control valve.

Steps

1
Purchase a new IACV gasket. You will need to replace the old one on your Honda IACV before returning it back to its place under the hood.
2
Locate the IACV. You will find it at the back center of the under hood area, near the throttle body (TB) and mounted on the rear of the intake manifold (IM). You will have to remove the TB intake hose in order to gain access to area of the IM that is connected to the IACV.

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3
Remove the Honda idle air control valve.^{[1]
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- Unscrew the 2 bolts attaching the IACV to the intake manifold. You will have to feel around for the lower bolt, which will be just out of plain sight.
- Pull out the gray plug from the right side of the Honda IACV.
- Remove the blue plug from the throttle body.
- Locate the coolant hose that attaches the IACV to the TB.
- Use needle-nose pliers to pull back the clamp that holds the coolant hose in place and then pull the hose out. This will provide enough slack to pull the Honda idle air control valve to the front so you can completely remove it.
- Detach the last 2 hoses from the IACV in order to free it for cleaning.
4
Remove the gasket from the Honda IACV and throw it away.
5
Examine the valve so as to identify the carbon build up that must be cleaned out. Note the areas with the heaviest concentration of filth, as you will need to pay special attention to them during the cleaning.^{[2]
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6
Clean the Honda idle air control valve. Spray the valve with the carb cleaner, being sure to thoroughly saturate the heavy buildup.^{[3]
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7
Allow the IACV to dry completely.^{[4]
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8
Put the new gasket in its place.
9
Reinstall the IACV going backwards through the uninstall process.^{[5]
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10
Adjust the idle control to its ideal setting.

Expert Q&A

Question

How do I know if my idle air control valve is working?

Hovig Manouchekian
Auto Repair & Design Specialist
Hovig Manouchekian is an Auto Repair and Design Specialist and the Manager of Funk Brothers Auto, a family-owned business operated since 1925. With over 30 years of experience in the automotive industry, Hovig specializes in the process of auto repair and maintenance. He is also very knowledgeable in common automotive issues and needs including engine repair, battery replacement, and windshield accessory and maintenance. Hovig's knowledge and hard work have contributed to Funk Brothers Auto winning Angie's List Super Service Award for five consecutive years.

Hovig Manouchekian

Auto Repair & Design Specialist

Expert Answer

If it's a modern vehicle, you can use an OBD2 scanner to check your idle air through scan tools for certain makes and models. You can also try to manually activate it to see how the car reacts—if something is malfunctioning, you can see if it's the valve or something outside the valve that's causing the issue. Sometimes the check engine light will go off, which can also help with the diagnosis. If it's an older vehicle, check the resistance that's going to the idle control valve from the vehicle; if it's outside of normal design numbers/parameters, you can isolate the problem accordingly.
Question

My motor runs rough and there's a smell coming out of the muffler. What's the problem?

Community Answer

You are probably burning oil. I would recommend taking it to a mechanic. They will tell you what's happening.
Question

How far down should I adjust the idle screw?

Community Answer

Do not adjust idle screw, that is set in the factory and shouldn't need to be adjusted. Fix the problem that is causing rough idle or whatever idle problems you are having. Something is likely broken, malfunctioning, or needs to be cleaned (IACV, vacuum leak, etc.).