2000 Ford F-150 Question: Started truck,the oil pressure light lid & needle stayed at 0 for about two mins

After 2 mins the light went off and the gage went back to normal. Also I am hearing a winding sound from the engine, like a pully is going out? I stop driving the truck as i don't want the engine to freeze on me. Do you think the oil pump is going out and where is the pump located? Thanks for any help