Has anyone experienced a fairly loud chirping noise problem on a 2002 LeSabre? the noise is intermittent - stops when brakes are applied - orwhen I activate the recirculate button on the AC - the AC or heat must be on. I can pinpoint the noise as "in the vicinity" of the alternator. Only occurs after highway travel exceeding 50-70 miles and can last for about five minutes before it stops. Noise changes pitch somewhat as engine revs increase or decrease. Not the rotors or pads as the noise continues when stopped and engine idling. So far two Buick dealers are clueless. The alternator and serpentine belt have been replaced with no effect.