Low oil pressure 4.0L OHV

[KGauger]

I picked up a '92 Explorer that had low oil pressure problems. I tried about everything and finally decided to have the oil pump and screen replaced. I took it to a repair shop and they pulled the engine, replaced the oil pump and oil screen, the rear main seal on the engine and changed the oil and oil filter. I drove it about 50 miles and I am experiencing the same problems. Tbe oil pressure will drop if you accelerate but may come back up in you let off on the gas. Also if you turn the engine off for a few minutes and then start the engine again, the oil pressure may come back up. The original oil screen was clogged but I can't believe a new oil screen is clogged atfer 50 miles. Any ideas?

Thanks,
Ken Gauger

 

[Willard]

are you referencing this by the gauge on the dash? if so, it is wrong. The gauge is more like a light, it is either on or off. So if there is any variation in it, it just means a connection is loose or the sensor is clogged up. In other words, unless you can hear problems, don't worry about it.

 

[KGauger]

Low oil pressure

I heard it. I had already replaced the oil pressure sensing unit on the block. The lifters were making a little noise with no oil pressure on the gauge. I tried to run a little farther and the engine started knocking. Afraid to run it any farther. I know that it is actually a switch and set about 6 PSI - grounds when there is enough oil pressure. I believe this is a real oil pressure problem.

 

[Jack Flash]

the oil pressure rising when you let off the trottle sounds like really worn out main bearings.

now that you have a knock, sounds like low oil pressure has gotten a rod bearing or two.

just an old junkyard dog and former teacher's opinion !