Symptoms of a Bad Idle Air Control Valve

A vehicle's engine consists of many components, all of which play a significant role in its overall function. One such component is the idle air control valve. Learn more about this part, symptoms to be on the lookout for, and how your local GreatWater-affiliated shop can help with any issues you face.

What is an Idle Air Control Valve?

The idle air control valve, or IAC valve, controls the air that enters the engine while the vehicle is idling. A key component of any engine system, the IAC valve works with other engine components to keep the engine running and throttle smooth when the car is idling. The main role of the IAC valve is to help the engine maintain a consistent idle speed so it's able to accelerate smoothly when it comes out of idle.

Key IAC Valve Symptoms You Shouldn't Ignore

If your IAC valve is on the fritz, the symptoms tend to be fairly clear. Here's what to be on the lookout for:

Unsteady Idle Speed

Remember, the main role of the IAC valve is to maintain consistent idling. If the idle speed is fluctuating or your engine is sputtering while in idle, it's likely an issue with the valve.

Hard Engine Start

Hard engine starts are another common symptom of a bad IAC valve, especially in cold conditions.

Random Engine Stalls and Shutdowns

If you're stalling out when you're stopped or in idle, a bad IAC valve could be the reason.

Poor Acceleration

IAC valves help maintain consistent idling, which helps with smooth acceleration. If your engine is misfiring or seemingly without power when you accelerate out of idle, an IAC valve problem could be the issue.

Persistent Check Engine Light

If your check engine light comes out, you should make it a point to get a diagnostic check - regardless of what you think the issue is. If it comes on and any of these other symptoms are present, the IAC valve could be the problem.

How to Diagnose a Faulty IAC Valve

While many of the above idle air control valve symptoms indicate a bad part, it's always best to bring your vehicle to a professional mechanic for proper inspection and diagnosis. Contact your local GreatWater-affiliated shop for more information and to schedule an appointment.

What Happens if You Ignore a Bad IAC Valve?

If you ignore a bad IAC valve, you'll notice immediate engine performance issues and a reduction in your fuel economy. If you continue to ignore it, it could lead to the failure of other key engine system components.

Repair or Replace?

In some cases, a thorough IAC valve cleaning may do the trick. This can remove carbon and dirt deposits, which can build up over time. In other cases, replacement may be necessary. Your local GreatWater-affiliated shop can help you determine whether the IAC valve can be repaired or if it should be replaced.

Facing IAC Valve Troubles? GreatWater Can Help!

If you have suspected IAC valve problems, don't wait for service. Contact your local GreatWater-affiliated shop today and schedule an appointment to have it inspected and addressed.