Just started today after a trip in the mountains, when I came down from the Rockies today my 2000 Jeep Cherokee Sport started to make a loud noise (grinding / rubbing gears) from the engine while stopped at a traffic light, the oil pressure gauge dropped very low. When the light turned green and I travelled forward oil pressure returned to normal and the noise stopped. Only to return when I stopped at the next light. Additional info the last few weeks when I start the car from cold there is sometimes a loud screech possible from the fan radiator area?

The dip stick oil level is high and about 1" above the safe area.

Any help or insight.

 

Sounds like you need a new oil sending unit. Its located right next to the oil filter.
Wow im dumb. Usually helps to read the entire post first. I would drain a little oil out though.

 

drain some oil, check your belt tension. Hope you aren't shearing anything off at the oil pump.

 

too much can be bad too, it will cause the crank to dip into the oil whipping it around making air bubbles in the oil then sucking them up your oil pick up tube creating air bubbles in the pick up tube