Oil pressure reading is wacked
My problem is once my car warms up, the oil pressure drops from 40 to redline. As I go faster it will stay around 40 but as soon as I slow down it drops, and while at a stop light it stays in the red. So I searched through the threads and see that using a Fram oil filter can sometimes cause oil pressure problems. I did have a fram and replaced it with a Mobil 1 High Perfromance. It was more expensive, so I figured it must be better right? My oil pressure sensor is a Delco sensor and was replaced in/around April by my Dad. I changed the oil last night with 10W30 and the new oil filter, and although the pressure looked better when it was cold, it still dropped a few mintues after driving it on the road. I would assume that this means the oil pressure actually is poor, and not just an indication problem?
Some history, this car had the crank turned and new oversized bearings installed back in Feb of this year, and it has new bearings and rings throughout. The car has 200K, but the engine is a junk yard engine with about 75K, and my dad went through it and cleaned her up. The indication problem started a little over a month ago. Does this mean an Oil pump is going? Do they go slowly like that or do they usually just go? My experience with oil pumps are on older cars from the 60'* when they were basically mechanically driven with 2 big gears. I assume they are different now? Any help would be greatly appreciated.