I have a 1992 ford ranger with a 2.3L 4cyl. I was having intermittent trouble with the oil pressure gauge jumping around. I removed the sender and hooked up a mechanical gauge. I read 20-30psi at 2000 rpm. This seems too low. The manuals say 40-60psi is the spec. After replacing the oil sender I have a stable reading of just over half way on the gauge. The engine doesn't sound like it has an oil pressure problem. The sending unit threads into the head toward the back of the engine. Is there perhaps less pressure at that point
then when the sending unit is closer to the oil filter. I got no where talking to the dealer. It just seems like if the pressure
not correct the gauge would indicate a low oil pressure condition.

The question is what should the oil pressure be if someone was to
remove the oil sending unit and thread in a mechanical gauge?

Any ideas?

 

40 to 60psi is @ 2000rpm. If you have at least 10psi per 1000rpm, you should be in fine condition.