me temp gauge rises and falls and the oil light comes on when the temp gauge shows hot

Is the engine actually overheating? Also, when the oil light comes on, do you ever hear knocking or ticking when the oil light comes on?

No to both questions it not overheating and the engine is not knocking or ticking. The temp gauge just rises then falls to normal and the oil gauge shows good pressure but the oil light comes on when the temp gauge is indicating being hot. I have changed the sending unit for the oil pressure and that made no change to the problem.

Did you replace the temp sending unit? It sounds like that is the root of the problem.