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2001 Ford Ranger XLT extended cab

When the temperature is below 32? overnight, the oil pressure gauge shows zero oil pressure for 30 seconds to a minute and then jumps up showing the proper oil pressure. I’m assuming there is water in the line to the oil pressure switch. Can anyone tell me the location of the switch and line? My solution would be to remove the switch, start the engine and immediately turn it off and replace the switch. I feel that should flush out the moisture in the line?

Not likely water in the oil sysyem (check your dipstick or under side of oil cap for a milky substance)State engine type. Replace sender with mechanical gague for test.

The oil pressure sending unit is near the oil filter. In the v6’s that is at the rear of the right cylinder bank. (You didn’t say what engine you have, so I assumed.) There is no “line.” The gauge takes an electric reading from the sending unit.

First of all, removing the sending unit and starting the engine is not a wise move. This will result in an oil shower in the engine compartment…and a mess in the driveway or garage.

Your problem is either a bad sending unit or a sticky gauge. To test for the latter, just whack the top of the gauge cluster before the gauge normally moves. If the needle moves, it’s the gauge. After you’ve ruled that out…

You should pull the sending unit and see if the opening in it is clear, as well as the port it screws into. If these are both clear, the sending unit is probably bad, but this is a fairly cheap fix for a new one. Just make sure you get a sending unit for a gauge and not a pressure switch for an idiot light.

Could just be the guage. My old 91 Explorer’s tach would not read in the cold, obviously the engine is running but the tach says 0 rpm. I think it’s just your guage but have a garage hook up their manual oil pressure guage, let it sit out in the cold over night, and compare what their diagnostic instrument says vs the dash guage. When you’ve proven that your engine always has proper oil psi then just pay no mind to your tempermental guage.