[JohnH]

as a professional wrench, its perfectly normal for it to cycle on and off. If its every few seconds it might be either over pressure or under pressure, but other than that, normal. if it sounds normal, and the clutch doesn't appear overly rusty in the contact surfaces(with associated rust all around when it gets worse), and its not noisy, along with the system making cold air, its fine.

If your mechanic said you might need a new compressor based on the compressor cycling, he is either incompetent, or trying to rip you off.