idle air control valve
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Idle Air Control Valve: What It Is and How to Know When It's Gone Bad


Cars are complicated machines. In fact, the average car has over 30,000 parts. So, there's bound to be a few that you haven't quite committed to memory yet. We've all got gaps in our automotive knowledge.

If the idle air control valve is one of your gaps, then you're in the right place. In this post, we'll cover everything you need to familiarize yourself with this piece of the engine including what it is, how it works, and common symptoms of a faulty one.

What Is an Idle Air Control Valve?

Fuel-injected vehicles, which include all diesel vehicles and most modern gasoline motorcars, require air in order to combust and power the vehicle. Several parts contribute to this process of air and fuel injection, but when a vehicle is at an engine idle, the responsibility falls on the idle air control valve. This valve allows air intake to the internal combustion chamber so that the engine continues to turn over, ready for more power.

How an Idle Air Control Valve Works

The idle air control valve, also known as the idle air control actuator, is an electronic component, which means that it receives its orders directly from the engine control unit (ECU). The ECU tells the air control valve how much air to let in according to factory specifications of the fuel injector. This control module and gasket combination is key in preventing engine stalls while idling.

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When an Idle Air Control Valve Has Gone Bad

Idle air control valves are intended to last the life of a vehicle. However, sometimes auto parts go out from irregular use and wear, which can lead to a few noticeable issues that will need to be addressed.

Your car should move forward at a consistent rate when you don't press the gas or brake. If your vehicle moves forward at irregular idle speed control, it could be a sign that your idle air control valve is going out.

Intense vibrations while idling or a rough idle ride might be due to an irregular amount of air flow and are other signs of a malfunctioning IAC valve. At its worst, a bad air valve might cause stalling. If your engine stalls, always visit a mechanic. It could be a sign of several major issues.

The idle control valve will trigger the check engine light. If you notice other symptoms of a bad idle air control valve and the check engine warning light is on, it's time to visit a mechanic for auto repair.

This post was originally published on September 4, 2019.

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