How To Clean Idle Air Control Valve Without Removing It?

An idle air control valve is an essential component that helps control the engine’s rotational speed. Unfortunately, carbon buildup can cover this component and reduce its effectiveness. This will require cleaning or replacing the component for optimal performance.

Cleaning engine components requires detaching them from other related components for proper cleaning. Most times, mechanics or car owners may prefer replacing them right away. However, detaching the component will cost extra time, and replacing it will cost extra bucks.

In the case of an idle air control valve, you can save extra bucks and time by cleaning it without removal. You can clean idle air control valve with WD40. Here, the Rx Mechanic team will walk you through how to clean idle air control valve without removing it. So, grab a seat and keep glued to this page till the end.

how to clean iac valve without removing

How To Clean Idle Air Control Valve Without Removing It – Step By Step Guide

Before we jump down to the procedures, I know you may ask, what is an Idle air control valve? What does it do? What are the symptoms? What if I want to lose the valve out and clean it on my garage table?

We’ve provided answers to all these and more in this well-detailed and informative article – Idle air control valve symptoms. You’ll also learn how to test an idle air control valve in the above article. Of course, your engine will not work fine when driving with a bad idle air control valve. That said, let’s focus on the topic at hand.

Before proceeding, get your hand gloves and goggles to protect you from chemicals and hot surfaces.

Step 1: Prepare your working area

This may sound silly, but it’s necessary. If you have just arrived from a long journey, allow the engine to cool before starting the cleaning task. You won’t want to burn off your hands. Put on your gloves before you proceed. Preferably, you can do the work before driving your baby ride that day.

Step 2: Find the idle control valve

Once you’re ready to clean the valve, the first thing is to locate the idle air control valve. If you don’t know the location of the valve on your vehicle, start tracing it from the air filter housing. The air filter housing is a large black plastic box that connects the throttle body. Your MAF sensor is connected to the air filter box.

Follow the air filter box until you locate the throttle body. The idle air control valve is usually attached to your throttle body, depending on your car’s make and model. On most vehicles, it is right below the throttle position sensor.

Step 3: Disconnect and remove the air ducts

First, you have to disconnect the air filter box. Start by disconnecting the clamps holding the filter and the cover together. After that, disconnect the wiring harness that connects to the MAF sensor.

After that, locate and disconnect all the vacuum hoses that link to the air ducts.

Step 4: Disconnect and remove the air ducts

The next step is disconnecting and removing the air ducts that connect to the throttle body by unscrewing the clamp. After that, keep the screws in a safe cup and shift the air duct to access the idle air control valve.

Before you proceed, check if the air filter is dirty or clogged. A clogged air filter will restrict adequate air flow from entering the engine, leading to a rough idle. It may be the reason for the rough idle. If the air filter is dirty, clean it and proceed to the next step.

Step 5: locate the air passage to the IAC valve

Look into the throttle body; there’s a small hole by the side. When the engine is idling, and the butterfly flang inside the throttle body is closed, airflow passes through this opening to the engine. Examine the small hole and see if it has a carbon buildup. Carbon buildup on that tiny hole will disrupt the seamless engine operation, especially on idle.

Step 6: Spray in some cleaning solution

Get a cleaning solution like throttle body or multi-purpose cleaner. WD40 can also do a perfect cleaning job. You’ll also need a tiny plastic brush that’ll enter the hole. Pls, don’t use a metal wire brush. It may leave marks on the throttle body or damage the passage.

Step 7: The finishing

Once you’re through with the cleaning, reconnect every component you removed earlier. Follow the reversal process. Ensure that you reconnect and tighten the screws that hold both sides of the air duct. Next, connect the air filter housing and all the hoses you removed.

How Do I Test An Idle Air Control Valve With A Multimeter?

If you’re getting error code P0505, which means you have a lousy idle air control valve, you don’t have to replace the valve right away. The problem may not come from there. So, you need to ensure the component is bad before replacing it.

Step 1: Disconnect the wiring harness

The first step is to test the electrical wiring that connects to the idle air control valve. First, disconnect the wiring harness. Get your multimeter. You want to verify that the wiring is transmitting power to the idle air control valve.

Step 2: Switch on the ignition

Turn the ignition to the ON position. Do not crank the vehicle. Test the connectors in the wiring harness to find they are usually six connectors. Now, test the no.2 and no.5 connectors. These are the up and down connectors in the middle.

Ground the black probe on a metal piece in the vehicle and test the two connectors. You should get around 12 volts. So 11.6 and above is pretty fine.

Check for a burnt or frayed wire if you don’t have power. A corresponding lousy fuse can also be the culprit. Yes, a malfunction in PCM can cause it. This is very unlikely, but it does happen.

Step 3: Unplug the idle air control valve

Switch off the ignition and unplug the valve. Now, turn your multimeter to ohms settings. Next, you need to perform ohms or resistance tests.

Step 4: Test the resistance

There are six connectors here – three on top and the other three on the bottom. First, place the red lead on the middle connector and the black probe on the other connectors on the same line. For instance, place the red probe in the middle and the black on the left connector. After, switch the black probe to the right connector.

Test the down connectors once you’re done with the upper connectors. You should have 30 ohms on each test.

Additional test

You can perform additional tests to ascertain if the idle air control valve is working fine. Remove the screws holding the valve and wiggle it off. Connect the electrical harness and place the valve on top of the engine. Have an assistant watch the movement.

Go inside the car and switch on and off the ignition. Make sure you don’t start the engine. The shaft on the valve should push in and out as you switch the ignition key. Watch this YouTube video for a visual presentation.


Q: What happens if I unplug the idle air control valve?

You may also ask, what happens when the idle air control valve goes bad? While the idle air control valve is vital, unplugging it will not prevent the engine from running. Instead, it will cause the engine to panic. However, it may cause a sudden increase and decrease in engine revolution per minute (RPM). You don’t want this to happen. It can be dangerous, especially for new drivers.

Q: Can a bad idle air control valve cause hard starting?

Yes, a faulty idle air control valve can cause hard starting. This is unlikely, but it does happen. The common sign of a bad idle control valve is rough idling. Whatever the symptom may be, don’t drive with a bad IAC valve for an extended period because it may intensify over time.

Q: Why is my idle going up and down?

Several parameters can cause your engine to go up and down when idling. If your engine fluctuates, even when you’re not depressing the gas pedal, you likely have a defective idle air control valve.

Other probable causes include lean engine, which is likely caused by defective fuel regulator or pump, vacuum leak, clogged or bad fuel injectors, and anything that can disrupt adequate fuel and airflow.

Q: Why does my RPM go up but car doesn’t accelerate?

Several factors can cause RPM to go up, but the car won’t accelerate. This is most likely a slipping clutch in manual cars and an indicator of a problem inside the transmission in automatic transmissions.

In manual tranny, if this happens when driving, you have a lousy clutch, shift linkage issues, or worn pressure plate. It is likely a bad valve body, clutch issues, or malfunctioning shift solenoid in automatic transmissions.

Final Words

Now you better know that how to clean idle air control valve without removing it is a simple process. Furthermore, it is a repair task that you can do without an assistant. However, I’d recommend you diagnose your vehicle with a scan tool whenever the engine performance reduces because several components can cause one fault.

If you have error code P0505 after the scan check, you have an idle air control valve-related issue. Test the valve, clean or replace it. The electrical harness may also be the culprit. So, make sure you examine them as well.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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