trying to determine what is making a squeaking/scraping sound. starts making sound after a few minutes running when the motor warms slightly. I've used a stethoscope to check PS pump, alternator, water pump, and vacuum pump but have not been able to find a source of the noise. noise sounds like it may be coming from the rear of engine compartment back towards where the engine and transmission meet.

have audio/video, but a 10 sec clip exceeds the maximum
uploadable size by about 10x