Hi guys:

I have a 2003 Ford Ranger Edge 6 cylinder- 76, 785 miles. Pretty well maintained.

Just recently, I've started hearing a "chirping" type sound (I don't think its a lifter/push rod): It seems to come from the alternator, or just behind, area of the engine compartment.

It seems to happen both in park and when the engine is warmed up; typically when transmission is engaged below 2000 rpm It starts somewhat quiet, then gets real chirpy, then goes away and starts over. It almost sounds like a plastic moving part or non-lubricated moving metal part. I've checked oil, radiator fluid and transmission oil which are fine and tried to find anything that might be loose. Having the heater on or off has no effect.

Any ideas?

 

Could be the tension pulley.