A/C compressor makes noise

And as I previously said I've seen compressors in my career that make noise at different speeds whether it be idle or higher Rpms . The methods I described previously will detect a low side starvation problem ... Gauges will show this along with temp readings along the suction pipe from EVAP to compressor .
Also did you notice how quick your gauges equalize after shut down ?
Did u notice any "pumping" or oscillating high side pressure especially when noise is present?