Idle air control valve replacement from $391
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Idle air control valve replacement
How much does an idle air control valve replacement cost?
When you are stopped at a set of lights with the engine running, or just after you’ve started your car, the engine will sit at a certain amount of revolutions per minute (RPM) - this is known as the engine idle speed, or idle for short. It is the job of the idle air control (IAC) valve to accurately control the amount of air entering the engine to keep this idle speed steady, ready for when the driver decides it’s time to move.
Turning on accessories such as the air conditioning, headlights or radio puts extra load on the engine, so the IAC compensates for this by letting in more air to keep the idle speed correct. When the IAC fails, the engine speed may fluctuate or stall completely, indicating it’s time for replacement. IAC valves vary in price and replacement can start from $150 all the way to $400 and above, depending on your vehicle.
What is an idle air control valve?
The IAC valve is an airflow device that is controlled via the Engine Control Unit (ECU) which monitors engine sensors to determine the correct idle speed for the conditions the engine is operating under. The IAC is usually a stepper motor which allows very accurate control of the airflow into the engine.
Adjustments are made whenever conditions change or accessories are switched on to prevent the engine from stalling. On older models, the IAC was connected to the cooling system of the engine, with a wax pellet fitted inside to control airflow with varying engine coolant temperatures.
Symptoms your Idle air control valve requires replacing
- Check Engine Light is on
- Erratic or irregular idle speed
- Engine stalling at idle
How is the idle air control valve replaced?
- The technician checks the vehicle to determine the issue
- The idle air control valve is located on the engine
- The wiring connector is removed from the valve
- The bolts holding the valve to the inlet manifold or throttle body are removed
- The old valve is removed and the port and mating surface is cleaned
- The new valve is fitted and the wiring connector refitted
- The engine is started and calibration carried out to ensure correct operation
Tips to remember:
- The idle air control valve port can block up with carbon. It can be cleaned out, but correct diagnosis is imperative to ensure correctly operating components are not replaced due to other problems
- Some Idle air control valves are part of the throttle body and cannot be removed. A replacement throttle body is the only way to repair these vehicles.
How important is replacing your idle air control valve?
A failing idle air control valve can leave your vehicle stalling at lights or when coming to a stop, which can be dangerous if you need to pull away quickly. Having your IAC valve replaced as soon as a problem is noticed will ensure your vehicle is in a safe, operational condition and running as designed.