Why Your Car’s Idle Air Valve is Sabotaging Your Fuel Economy

Sun, 03 May 2026 02:53:25 +0000

Why Your Car’s Idle Air Valve Might Be Sabotaging Your Fuel Economy If your vehicle idles longer than usual, stalls unexpectedly, or experiences rough engine vibrations, the idle air valve might be the hidden culprit—and behind it could be a malfunctioning idle air control valve (IAC valve). This small but critical component plays a major role in maintaining proper engine performance, especially at idle and during low-speed operation. Understanding how the idle air valve functions and why it affects fuel economy can help you catch issues early and keep your car running efficiently. ### What Is the Idle Air Valve, and How Does It Work? The idle air control valve (IAC valve) is a sensor-like device situated in the engine’s intake system. Its primary job is to regulate the amount of air entering the engine when it’s idling or running at low speeds. By adjusting the air supply, the IAC valve ensures the engine runs smoothly without stalling—even when the throttle is nearly closed.