2002 2.5l no oil pressure on gauge. Runs fine...no

Complete engine teardown.

I would suggest checking with a manuel gauge. The sending unit may be bad.

It is probably your sending unit, if your engine hasn't started knocking or seized by now it is probably fine. Either change the unit where it sits or have a technician check for oil pressure with a mechanical gauge.

The oil pressure specification for your engine is 13 PSI at idle hot, 37 to 75 PSI at engine RPM higher than 1600. I suspect your oil pressure gauge sender unit or gauge is inaccurate. I would have a known accurate mechanical oil pressure gauge temporarily screwed into the present oil sender unit to verify actual pressure.

If you have the correct pressure I would replace the sending unit first.

u Have a problem with the oil sending unit. The sensor is located beack right side of the engine block. Take out the switch and make sure u have good oil PSI. Should be 6 psi at idle and around 50 at 4000 RPM. If the presure is ok replace the switch they are very cheap about 20 bucks. Please rate.

Wire on oil sending unit may have fallen off or sensor itself may have gone bad. Check both. If engine has no tapping noises, likely it's not a pressure problem.

When the gauge is at 0, is there any noise from the engine (tick, knock etc?) I would have someone put a mechanical gauge on there and read true pressure.Your driving pressure seems OK but if the low number is "real" something is wrong!

If grounding the dash does not work, try putting a mechanical gauge on it and reading actual oil pressure. Pressure does change while driving, but should not wander. With mechanical gauge, check that running hot at idle (in gear if automatic) pressure should not drop lower than 15psi (I'd rather see 20) High reading should be around 40 -50 but no higher.Low pressure indicates a loss of supply or bad bearing on the crankshaft, high pressure may be caused by sticking pressure relief or restriction in an oil passage.

The gage is working because it is coming on sometimes. The oil pressure sending unit on the engine is starting to go. I would replace the oil pressure switch on the engine first.

depending on the weather, and how cold it is, oil pressure will run high until it warms up. now if it still runs high after it warms up then its most likely the oil sending unit.