A/C compressor makes noise

Don't have a pic of the valve at this time. It sits inside the suction port side of a Chrysler RV2 compressor. I think its called a EPR valve. It works like a suction throttling valve on a Ford or a POA valve on a Chevy A/C system. This valve is needed in a non-cycling clutch system to prevent the expansion valve from freezing up - I think. Original compressor was marginal and in unknown condition ( this was a junkyard car purchase). New compressor was an exact replacement except set up for R134A. Yes, flushed the system. New expansion valve, accumulator / dryer, 6 oz. pag oil. Charged the system with 3 lbs of R134A. Tag on old compressor called for 3 lb, 6 oz of R12. Yes, used a R134A gauge set. High side at 210psi and low side around 30psi. with ambient around 96 degrees. Made sure the sight glass on the accumulator had no bubbles in it. Didn't do vent temp. It looks like this valve may be adjustable? I will take a pic when I blow the system to inspect this valve.