Another oil pressure thread, low pressure with little fluctuation. (1 Viewer)

[Tigli]

I've been looking but haven't found anything consistent with my situation.
Driving the 1997 LX the other day and noticed there was minimal pressure registering. Immediately shut it off and thought about it a minute. No weird noises, no loss of power, everything working other than the gauge. After stating it again I had slight increase in pressure. Took it home and determined it to be the sender after checking all wires for continuity. I replaced it a couple days later with no improvement. With initial start up I have hardly any pressure if I then shut it down and re start I have improved pressure but no variability with RPM. I have since checked the gauge which works well.

Where I am now. Pressure on start up is just below the middle line, needle has minimal variability with driving. I suspect that I may be dealing with a stuck open relief valve or some sudden blockage...

I'm running 10-30 mobil one dino oil. Oil is full.
Thoughts appreciated.
Tigli

 

[sl3807]

It may be a faulty gauge on the dash. Mine has been the same for over 2 years, PO even replaced the sender. I have had my mechanic check the oil pressure numerous times, everything checks out fine.

 

[Tigli]

My initial thought also but then I checked the sender to gauge by grounding the gauge and applying pressure to the sender resulting in appropriate readings on the gauge.
Get this, posted this and then drove to napa to buy a new filter. put it in and got normal readings. Drastically different than where its been. So at this point its either a bad filter or tapping around the relief valves loosened one of the two valves (I know how the valves work and most likely they would stick in the closed position but it was worth a try). I'm leaning toward the bad filter...
t

 

[Howard705]

Need a mechanical gauge to test actual pressure

 

[Shwing]

Is the sending unit the only thing that triggers the dummy light? As soon as my truck warms up, oil pressure gauge drops to zero and oil light comes on. Gauge only goes up to 1/4 when I accelerate. Replaced the sending unit but it still happens. No other symptoms so I obviously have oil pressure. Wondering how to fix this...

 

[cruisercommando]

My wife's '93 had a similar issue on a newly rebuilt engine. Turns out the piston for the bypass valve in the cooler was stuck. Once I pulled the oil cooler cover off and replaced the internals, the pressure was in the "normal" range again.