Wise Car-Owner: Is The Problem Your IAC Valve? Fix It Yourself

Posted on: 11 May 2015


The IAC valve or the idle air control valve is an important part of your vehicle, and it is easy to replace. This little compartment regulates the amount of air that goes into your engine while it's idling. The following guide will show you a few signs that your valve has gone bad and how to replace it.

Symptoms Of A Bad IAC Valve

Look out for the following signs of a bad idle air control valve:

  1. The IAC valve is meant to take care of the air going into your engine for proper fuel combustion. But, this function is severely affected when it goes bad. You may notice that your engine shuts off or stalls when you turn on your AC while idling. Turning your AC on has a small effect on your idle speed, which could stress it and force your car to stall.
  2. A bad valve may cause rough idling or just low idling, which is usually under 800 rpm's.
  3. Yes, your engine light might also come on. Have your auto care specialist read your engine light to find out what the problem is.
  4. A clogged or faulty valve might make it harder for your car to idle correctly, which could translate to jerky deceleration when your car returns to idle speed. Or you might also feel a slight hesitation when accelerating from idle speed.
  5. The improper air mixture within your engine could cause a backfire in your tailpipe because of the excess gasoline.

Remember that some of these symptoms could also be related to other issues. So, talk to your auto care specialist to confirm your suspicions.

Replacing Your Own IAC Valve

You will need the following:

  • Your owner's manual
  • A new IAC valve for your vehicle from your local auto parts store
  • Safety glasses and gloves
  • Socket set and wrench


  1. Park your vehicle in a location that is safe to work in. Make sure you let it sit long enough to let the engine cool to work on your car easily.
  2. Open up your hood, and locate your IAC valve. It is usually by the throttle body, and it looks like a tube with two small wings on the edge. You can use your owner's manual to find it, too.
  3. Put on your glasses and safety gloves.
  4. Remove the negative or red cable from your car battery, for your protection.
  5. Use your socket wrench to remove the two bolts holding the IAC valve in place.
  6. Replace it with your new IAC valve, and bolt it in place.
  7. Reconnect your battery, and you are done.

Hopefully this fixed your issue, and you've saved some money doing it on your own. For more information on auto parts, contact Yearwood Performance Center.