How To Clean An Idle Air Control Valve – Dive Thru Without Stalling

broken car

Stalling at the drive thru is one of those things you want to avoid especially when it is late or the queue is long. I never heard of anyone getting a ticket for it though but it gives that bad rep everyone avoids.

Back in the day when vehicles used carburetors to control fuel intake the idling (RPM when parked) was controlled using a tiny screw. This screw is aptly named the idle speed actuator much like the hook attached to the accelerator cable it was quite cumbersome.

Fast forward to direct injection engines and the idling is controlled using the idle air control vale. The objective is the same they allow air through past a closed throttle plate – the engine keeps running but it will not turn the wheels.

When the idling is off the vehicle often stalls irregularly or shudders inconsistently while idling. This happens when the valve becomes dirty or clogged with small carbon particulate matter.

If you are experiencing any of the above symptoms, you should have the valve cleaned or better learn how to clean an idle air control valve.

Essential Tools & Equipment: How To Clean An Idle Air Control Valve

1. Carbon Cleaner

Here is another of those products you can experiment with on your DIY task. Ask about the varieties when shopping and share your experience in the comments.

2. Old Clean Rag Or Cloth

Old clean rag or cloth

Micro fiber is best for cleaning cars, leaves no scratches.

3. New Gasket

New gasket

Gaskets are one of those very specific engine components. As much as possible, do not spend on anything but the exact match. Newer models may have similar looking but difficult to fit options.

4. Screwdriver


5. Wrench


How to Clean the Idle Air Control Valve

Step 1 – Locate The IACV

Locate The IACV

The IACV vale is positioned along the main intake on the rear by the throttle body.

It has a sensor and electrical wires attached – if unsure check the vehicle owner’s manual.

Step 2 – Remove The Intake Hoses

Before beginning, cleaning it is advisable to remove the intake hose. It may have some fuel and can cause a spill or worse.

Step 3 – Disconnect The Negative Terminal Of The Battery

Disconnect The Negative Terminal Of The Battery

Just remove the cable attached to the negative terminal on your battery (terminal marked -). If unsure, once again refer to the owner’s manual. This is VERY important given the electrical circuit controls the underlying computer chip. You do not want to risk ELECTRIC SHOCK or ERRORS messages when you have finished cleaning the component.

Step 4 – Remove The Screws That Hold The IACV In Place

Remove The Screws That Hold The IACV In Place

With your screwdriver, gently remove the screws that hold the IAVC in place. As you do so ensure they are all firmly in place and pay attention to any carbon particulate matter coating the screws or underneath.

Often the IAVC valve is attached with 4 screws and has cone shaped tip protruding from the center – pintle. The valve extends through an opening just before the butterfly valve. Air regulation occurs as the pintle moves and out of the IAVC – this regulates the air and idling of the stationary vehicle. The valve movement is computer controlled.

While you cannot change this speed, the grime and carbon dirt clogging the component is often the reason the component does not operate as required.

Step 5 – Disconnect The Electrical Plug

Disconnect The Electrical Plug

This may be tricky given you may need to squeeze to get the component loose.

Step 6 – Remove All Other Plugs From The IACV

These in some cases may include the electrical wiring components attached to the device.

Often there are three wires, one controls current, the other is grounding and the third leads to the computer chip control unit. Mark the wires just in case to ensure you replace everything correctly when reassembling.

Step 7 – Take Off The Gasket

You should trash this once you have confirmed the new gasket is a match.

Step 8 – Spray The IACV With The Carbon Cleaner

This should loosen any grime and particulate matter on the valve – the reason idling is running off key. Use the rag to clean off any grime or oil on the IAVC. Repeat the spraying and cleaning until the component looks clean enough to filter the air into the intake.

Step 9 – Clean The Passages That Connect To The IACV and The Throttle

Spray the cleaner on the rag and clean both surfaces – allow them to dry before placing the gasket in place once more.

Step 10 – Reconnect The Hoses

Reconnect The Hoses

These are the hoses removed in step 2. Ensure all components/hoses/screws reconnected are attached firmly and is clean as you reassemble the intake unit.

Step 11 – Reattach The IACV

Return the screws/bolts in place ensuring they fit snugly as before.

Finally reattach the coolant hose (the one you had to squeeze) the battery and start the engine to test the idling. If the procedure is completed properly you will have a steady idling (consistent) and the stalling should end.

However, it is possible to begin experiencing inconsistency while idling soon after. In this case, you should refer to a trained auto technician to test and provide you with a permanent solution.


vehicle fixer

Maintaining a smooth running engine is always a joy for vehicle owners. Unfortunately as your vehicle ages more and more components begin to fall apart. Often these minor errors will be spotted and replaced during your scheduled checks.

However, what about when these occur unexpectedly. You do not always have the time to have the car sent to the garage and you should learn to do some of these routine tasks.

You will be surprised how many times you can clean a dirty IACV valve using $200 carbon cleaner. One visit for just this could well have you paying the same amount.

This guide highlights EVRYTHING you need to know about cleaning clogged IACV. It covers how to find and safely remove the valve and attached wiring, unscrewing and cleaning the component, replacing everything and testing the engine.

For injection vehicles the guide is very clear, however, for older (carburetor) vehicles the process is simpler though these instructions may be partially incomplete.

Please share your experiences and the differences in the comments to provide a comprehensive - how to clean an idling air control valve post. Thanks.

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