When you get your compressor changed or if you are doing it yourself. Are you self charging it? or taken to a shop with a proper AC machine. Also last time did you change the receiver dryer and the orifice tube as well? Those other two items if not replaced should be changed out with the compressor for good measure, both are cheap. Also if its overcharged you could be overworking the compressor if your just doing this yourself and not using a machine, by now the system could be full of alot of AC oil and just pushing the compressor hard.