Idle Air Control Valve
Idle Air Control Valve (Appearances Vary) Step 2 - Internal air ports are used to regulate the volume of air allowed to pass through the valve. Some valves feature a coolant passage used to heat the valve for improved economy. These ports are sealed using a gasket which prevents the valve from leaking.
Air and Coolant Passages Step 3 - Air passage bypass ports are used to route air past the butterfly and through the idle air control valve.
Throttle Bore Air Passages
Coking Condition Helpful Information When an idle air control valve fails it can cause the engine to idle erratically and even stall. Sometimes a weak idle air control motor will can cause engine problems without triggering a MIL (check engine) light. Inspect vacuum lines when servicing the idle air control valve and replace any that are broken or dilapidated.