Why does a 2002 Mercury Sable make a chirping sound when it is idling?

Answer 1

Answer

the most common reason for this sound on this car is a defective camshaft position sensor synchronizer. The bearing lacks lubrication and eventually chirps as you describe. I've replaced about 20 over the past year at my shop. it's located underneath some wiring directly underneath the throttle body. if you place your ear near the throttle body where the intake tube connects i think you'll find the noise from there. i would recomend that you have a trustworthy shop do it for you because it has to be "timed" , you can't just remove it and replace. not to expensive anymore. they can be bought from any parts store. a company called Dorman makes them aftermarket now.

Answer

Probably bad Camshaft position sensor synchronizer. It's located under wiring harness directly below the throttle body. Put your ear near throttle body and youll hear it right below there. Extremly common for this car. Have a shop replace it because it has to be in "time" you can't just remove and replace. Not very expensive anymore. Dorman makes aftermarket units that can be bought at any auto parts store.

Could also be a bushing in the alternator.