The Idle Air Control valve (IAC valve) is an electromechanical component that meters airflow through the engine when at idle in order to keep the engine running. The IAC valve attaches to the side of the Duratec V-6 intake manifold and is operated by the engine control unit. The IAC valve is susceptible to failure from oil or sludge over time. IAC valve problems typically lead to uneven engine idling--the engine sometimes can stall when the driver's foot is not on the gas.
Things You'll Need
- 8mm open-end wrench
- Replacement gasket
Removing the IAC Valve
Disconnect the battery.
The IAC valve is the silver tube-shaped assembly on the firewall side of the upper intake manifold. Remove the wiring harness clip on the IAC valve to disconnect it from the ECU.
Remove the upper bolt from the IAC valve. Next, carefully work to get the wrench on the lower bolt on the IAC valve. This is difficult to see and reach, so be patient. An angled wrench may make accessing the bolt easier; also, with the top bolt removed, you may be able to pivot the IAC valve assembly to get to the lower bolt more easily.
Make sure that any remaining gasket material is removed from the upper intake manifold and and from the IAC valve (if you plan on reinstalling it).
Replace the IAC valve by reversing the order of the removal process. Be sure to use a new gasket and to torque the mounting bolts equally, in order to avoid vacuum leaks.
Tips & Warnings
- The IAC valve can be cleaned of internal gunk, such as oil, but typically, replacement is the best way to fix any idle issues.
- Be careful not to drop the wrench or bolts! The firewall side of the Contour engine bay is very difficult to access.
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