good oil pressure, oil light on?

  • jjohns1508
    jjohns1508
    Junior Member
    • 10
    #1

    good oil pressure, oil light on?

    Recently (two weeks ago) I rebuilt the motor. Replaced the oil pump. verified the oil pressure was 30 psi at idle and up to 60 while driving with a mechanical gauge.
    I was driving it tonight and the oil pressure light came on. The oil pressure was 30-60psi as normal (based on the factory gauge).
    No engine noises. I drove it for another 10 minutes or so and parked it.

    Any ideas why the light would be on but I have good oil pressure. BTW I replaced the gauge when I rebuilt the motor. Rock Auto special.
  • 86twoplustwo
    86twoplustwo
    Member
    • 53
    #2
    Those sending units are notorious for going bad. Maybe try replacing it with a Nissan brand sending unit, but sometimes even those have problems. I wouldn't really worry about it.

    After I replaced mine the light stopped coming on but the gauge still doesn't give a good reading.
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  • Pdfflyer
    Pdfflyer
    Junior Member
    • 22
    #3
    Take oil pressure off the engine again, soak the inlet side overnight in a product called marvel mystery oil, that should loosen up the inlet side. Replace it on the engine next day, and write me again.... Works for me. I continue to use marvel mystery oil as an additive every oil change.
  • Marissasimos
    Marissasimos
    Senior Member
    • 160
    #4
    Was this issue ever resolved? What did it end up being?
  • 88sinZ
    88sinZ
    Senior Member
    • 2019
    #5
    Remove and clean out your pressure sender with some brake cleaner, it's a pressure diaphragm with a small orifice to dampen fluctuation - this makes it prone to clogging after rebuilds. Drill it out a little if you really want.

    worst case scenario test pressure with a manual gauge.
  • Marissasimos
    Marissasimos
    Senior Member
    • 160
    #6
    ^ personally I already did that twice and also tested with a manual gauge, my pressure is good but alas i still get the light staying on after I start it. Maybe I need to go with a different brand sending unit?
  • 88sinZ
    88sinZ
    Senior Member
    • 2019
    #7
    Ref. FSM EL-87 for testing. it's a simple resistance test. beyond that you should test continuity and electrical source.

    i had the same prob, cleaning out the unit worked in my case.
  • Parker
    Parker
    Senior Member
    • 966
    #8
    Hey, this is maybe a stupid question, but do the dashboard and the oil pressure guage actually both get their signal from the same sensor? Before I replaced it, my original oil pressure sender was pretty erratic and would often just drop from normal pressure to zero, then jump back to normal again. The dash light never came on during any of these times that the sensor was sending a zero pressure signal.
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