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2002 Mercury Grand Marquis
Question: idle speed control
Answer #1Brian Glastetter January 25, 2011, 20:58Master
Idle air control valves on Fords sometimes fail in a way that make them hum or moan. While the car is making the noise you are talking about, place your hand on the air filter housing. If you feel a vibration relative to the noise, then the idle air control valve has failed.