How to Clean a GM IAC Valve

Your GM’s Idle Air Control valve, commonly referred to as the IAC valve, is responsible for controlling the engine’s idle speed. Over time, the IAC may become dirty and need to be cleaned. You will know when your IAC needs to be cleaned when your GM vehicle stalls or has a strange idle compared to normal. Cleaning the IAC valve can be done by a local mechanic, but to save time and money you can follow a few simple steps and clean the IAC valve yourself.

Things You'll Need

  • Owner’s manual
  • Socket wrench
  • Throttle body cleaner
  • Allow your GM vehicle to cool for at least 20 minutes before you begin any work under the hood.

  • Locate the IAC valve, which is attached to the throttle body of your vehicle. The valve is a cylinder unit, about three inches in length. Refer to your owner’s manual for exact location and a diagram.

  • Unplug the IAC valve harness. Use a socket wrench to remove the two bolts that hold the valve with the mount. Pull the IAC valve out of its mount.

  • Spray throttle body cleaner inside the holes on the IAC valve. Use a wire brush to clean away any built up carbon or debris.

  • Place the IAC valve back onto the mount, replace the bolts, and tighten. Reconnect the harness and close the hood of your GM vehicle. Your vehicle is now ready to be used.