Among the most terrifying car failures are faulty idle air control valves, also known as the IAC valves. Whenever this part has deteriorated, your vehicle may idle rough and occasionally splutter.
An ideal air control valve can go bad at any moment. As a result, you must fix it immediately and be aware of any indicators of a faulty idle air control valve.
Otherwise, you risk hurting yourself, your passengers, and your fellow drivers on the road.
What Is An Idle Air Control Valve?
The idle air control valve is attached to the accelerator on fuel-injected vehicles, controlling the flow of the air to enable the car’s effective idling.
Whenever the throttle plate shuts while idling, the air control valve, also called idle air control actuator, injects air around the plate, resulting in a flawless stopping of the car.
To use their fuels, the cars’ engines need air.
Nowadays, all the vehicles have an installed system that transmits signals to the idle control actuator whenever the vehicle is parked or has temporarily stopped, for example, at a ‘Stop’ sign.
That way, the actuator is adjusted to let the proper quantity of airflow to the fuel tank.
Whenever all the parts of the car system work properly, the idle functions smoothly too, the RPMs present little to no fluctuations, and the car makes no revving or sputtering noises.
What Happens If The IAC Actuator Goes Bad?
If an idle control actuator fails, the indications might be slight at first. If you are stopped at a red light or a ‘Stop’ sign, you might find that the engine sounds gruff at first.
And if the vehicle is idle too, it could also make a distinctive noise.
In extreme circumstances, your car might stop suddenly in the center of the road, and you might not be able to turn the engine on again.
When idling in traffic, a vehicle with a faulty idle air control actuator is more susceptible to stalling.
Stopping while drivers following your car are not aware that you are facing an automotive malfunction might lead to an unfortunate situation as it might lead to a car accident.
It is significantly more difficult to repair your car if it stops on the motorway, so whenever you notice a problem with the IAC actuator, really try to avoid driving on the highway.
A malfunctioning car is unsafe no matter where you are, but it is especially deadly on an interstate’s major routes.
What Are The Symptoms Of A Failing IAC Valve?
When the IAC valve breaks, it can create a variety of problems with the car, even rendering it unrideable in some situations.
A faulty or malfunctioning IAC valve will usually cause a few indications that may warn the driver of a possible problem.
Inconsistent Idle Speed
Changing idle speed is among the most prevalent symptoms linked with a faulty IAC valve. The IAC valve is set to control and keep the motor’s idle speed consistent.
If it breaks or has any problems, the idling speed might go crazy. This can cause idle speed extremes, or, in certain situations, alternating highs, and lows.
The ‘Check Engine’ Sign Is On
If you see that the ‘Check Engine’ sign is on it might mean that there is a problem with the IAC valve.
The Check Engine Light can be triggered by a number of problems, therefore having the car’s computer inspected for trouble codes is strongly advised.
If the car’s engine starts stalling, that is certainly a way more significant indication of an IAC actuator’s problem. If the IAC valve completely dies, the car may be left without a source of air to keep the car idling normally.
This can cause the vehicle to stop while it is moving, and in certain situations, it can cause the engine to not run at all and stop the moment it starts running.
A defective IAC valve will typically present symptoms that are evident enough for the driver to realize that there is a problem with the car.
If your car exhibits any of the issues described in this list, or you believe that the IAC valve is malfunctioning, it is best to get it checked by an expert mechanic rather than doing it by yourselves.
What the professional technician will do is run some tests to see if there is indeed an issue with the idle air control actuator.
If there is indeed one, then they can proceed with replacing it, and that way you can be absolutely certain that your car will be restored to normal and you will be able to drive on the streets without putting yourself or anyone else in danger.
Where Is The Idle Control Actuator?
Every car brand and model is unique. As a result, you must read your owner’s handbook to determine the precise placement of the actuator in your car.
It typically attaches to the throttle body next to the intake manifold on the majority of vehicles and is located on the upper side of the center of the car’s engine.
In case you are not able to find it, you must seek the advice of a qualified technician. Employing a service specialist is nearly always cheaper than having to pay for faulty DIY maintenance.
However, if you are confident about your skills and want to repair it on your own, you might be better off watching a “how-to” clip first of a Youtuber repairing a car of the same brand, model, and year.
Typically, you will spot it by tracing the air filter hose at the top of the engine. Typically, you will spot it by tracing the air filter hose at the top of the engine.
Ensure that the car’s battery is disconnected prior to operating on the idle air control actuator or any other electrical part of the car.
How To Troubleshoot The Idle Air Actuator?
If you discover that your idle air control valve is not working properly, it is best to try a couple of things before replacing it.
These suggestions may assist you in getting your automobile moving so that you can drive back home or to your technician because if you don’t repair it immediately, the damage might be permanent.
Moreover, if you intend to fix your IAC valve alone, you must complete all of these stages.
Run Tests To Your IAC Valve
Sometimes, the indicators of a failed IAC valve might be obvious. Nevertheless, depending on a number of different conditions, you might fail to notice that this component needs repair.
Hence it is best to run some quick tests every now and then to assess the condition of your IAC actuator.
To begin with, switch your radio and AC system off to listen to the noise your vehicle produces.
After that, note down the car’s RPMs, as any vehicle that takes on passengers must not have RPMs more than 1,000 or less than 600.
In case the car’s RPMs are too high, it is probably because the idle air control actuator needs to be cleaned or changed.
If the RPMs are less than 600, however, it might mean that there is a vacuum leak in your car or that there is an idle air control actuator malfunction.
How To Reset Your IAC Valve?
Reconfiguring your idle air control valve might assist you in getting your car running again.
The setting of the valve pintle regulates the airflow into your motor, and the IAC valve will not perform adequately if the pintle positioning is wrong.
In case that happens, you must reset the IAC actuator. To do an IAC actuator reset, follow these steps:
- Start your car.
- With your car in ‘Park’ mode, fully press the brake pedal (till it cannot go any further down).
- Then, gradually begin to let go of the pedal by slightly decompressing it.
- Keep your car’s engine on for another five seconds.
- After that, switch off the engine and wait 10 seconds.
- Lastly, restart your car and check to see whether it is idling properly.
If you have a drive-by-wire car, you may be unable to turn its engine on unless the throttle body valve plate is rebooted.
If that is the case, then you must follow the procedure for resetting it specifically to your car. Alternatively, seek the assistance of a trained technician.
How To Clean Your IAC Valve?
Carbon and other pollutants produced by your motor throughout ignition might accumulate in the idle control valve over time. The debris might interfere with the valve’s operation.
Keeping your intake air control actuator clean will assist it to operate normally. It is a very simple thing to do that will help you check this car part.
Before you begin, check your car’s handbook to ensure that you could put carbon cleaners on your vehicle. In addition to that, you will have to get the following tools:
- A wrench
- A flathead screwdriver and one with a Phillips head
- An automotive cloth
- A carbon cleanser
- A replacement gasket for the IAC actuator
After you get these tools, you need to ensure that you take basic precautionary measures.
For instance, if you’ve driven your car a few minutes before you decide to clean it, then you must hold on till the engine has totally cooled to do so.
You should also use protective gloves and safety eyeglasses to make sure the chemicals will not go into your skin or eyes.
Once you are finished, disconnect the IAC valve by following the instructions we will provide you with further below in this article.
Next, adhere to the guidelines on the carbon cleaner’s bottle as well as to the directions of your car’s handbook.
When you have cleaned the parts, replace the component according to the guidelines and run some tests on your vehicle.
How To Clean Your Throttle Body?
If your vehicle continues to idle badly, you will probably have to entirely clean the throttle body.
This is especially true when you see that your gas pedal is a bit stuck at points, as carbon accumulates inside the throttle body, exactly in the same way it does on the IAC actuator.
Whenever this happens, a gooey carbon layer forms on the throttle plate, causing the pedal to feel as if it is sticking.
However, having to clean the throttle body is not as simple as having to remove and replace that idle air control actuator.
You must follow the particular instructions provided for your car’s year, manufacture, and model. However, the following actions are required:
- Remove the throttle body hose.
- Take out the air cleaner.
- Disconnect the air control and position by grabbing the tabs on both sides of the throttle body.
- Subtract the throttle position detector.
- Detach any water lines from your car.
- Unplug the throttle body cables carefully so that they do not come into contact with any other parts.
- Detach the throttle body by removing the bolts.
- Remove it with caution so as not to damage the seal.
- Take off the seal.
- Follow the directions on the carb cleaner.
- Replace the components.
Replace The IAC Valve
If your car stalls, you most probably have a faulty actuator. In a scenario like this one, you must uninstall and replace the faulty part.
As we previously mentioned, changing the idle air control valve is significantly easier than uninstalling and cleaning the throttle body.
Furthermore, the throttle control valves are a low-cost component. Therefore, before fully cleaning the throttle body, you may also want to consider buying a new one to replace it.
Yet, even in that case, make sure to clean the IAC actuator seat prior to reinstalling the new throttle body to avoid getting the replacement component dirty.
When replacing the IAC actuator, you must follow these steps:
- Unplug your battery wires.
- Find and remove the wiring harness electrical terminal.
- Remove the idle air control actuator
- Clean the valve’s seat.
- Rejoin the wire harness connection and swap the IAC valve.
Following the valve’s replacement, follow the instructions to reset it.
How Much Does It Cost To Repair The IAC Valve?
IAC valves are reasonably priced. They might cost as little as 30 dollars or as much as 400 dollars. If you leave your car to a mechanic, the cost should be less than 100 dollars.
However, if you do it yourself, you will also have to buy a carbon cleaner, which costs a few bucks.
The Bottom Line
If your car starts but you see that idling is hard, you must clean the IAC actuator. If your car is not stalling and the gas pedal is stuck, you should clean both the throttle body and the IAC actuator.
However, if you see that your vehicle is stalling, the best thing you can do is replace the IAC valve.
Keeping the throttle body of your car in perfect condition means that cleaning, repairing, and even replacing the parts of the car’s system will have to be done on a regular basis.
If you see that your car is in need of repairs or that some of its parts need to be replaced, it is advisable to proceed with these actions as soon as possible in order to avoid any further troubles.
If you neglect these issues, then the faulty components might lead to bigger malfunctions, and driving your car can be risky not only for you but also for your passengers and fellow drivers on the streets.
Therefore, always be alert and conduct frequent tests on your car to check that everything is functioning properly.