1997 Olds Achieva problem

Ok. I think I have a problem with my car. It is a 1997 Olds Achieva SL, the 2.4 4cyl, sedan, with 97,367 on the odometer (funny story, the actual mileage is around 69,XXX. A few years ago, when my dad was driving it, there was a constant problem with the check engine light. So he took it to a mechanic, a long time, lazy friend to fix it. His friend actually owns the shop, and has a few mechanics working for him. So, one of the mechanics said that to get rid of the light, he had to change the gauges out. So my dad said ok, and the car got a gauge assy. that had 83,XXX on it, and the light "supposedly" went away. After many years of learning, I wish he never did that, and should have just had the trouble codes read, if any found.:fall Anyway, long story short, I keep thinking the A/C compressor is going bad. How can I tell if it is. The car sometimes will make a slight pinging/hissing noise, but not all the time. I will try to get a video up in the next couple of days with the car running and the noise. Thanks very much. Please help!!