Low Oil Pressure

[lilmx5]

Hi,

 

I drive a 2005 Nissan Pathfinder SE and when I first bought it, it had a timing chain issue. After fixing the problem, I had very low oil pressure (this could have been a problem before I had bought it and I never noticed). I tried my go at waiting till it got better but then it got worst. There was other problems with the engine so finally we rebuilt the motor. At this point I'm 3 grand in, freshly machined motor inside of the car with a brand new expensive oil pump and after 120 miles of break in, the oil light comes back on. Everything about the engine was perfect and 3 mechanically trained people put it together. At this point I'm stuck not knowing what to do. Everything oil related was fixed, even the passage was and I just don't know what to do. The light only comes on when I am stuck at a stop light, and then goes away when I start driving. What can I do?

[Mr_Reverse]

I suggest starting with a pressure test. Find out what the actual oil pressure is. If a test gauge shows good pressure, then I would suspect a faulty sensor or wiring. If the pressure is low, either there was a mistake in the engine rebuild or a problem with the pump or pressure regulator. 

 

Is the engine running normally and not giving any codes? Usually low oil pressure will cause cam timing codes since the phasers are sensitive to oil pressure. If they are happy, odds are the pressure is good. 

Edited January 31, 2021 by Mr_Reverse

[adamzan]

I would start by confirming the sending unit is good. Do a test with a mechanical gauge like Mr Reverse suggested. The sending unit in my 95 was bad and it would throw the oil light on unless you were driving on the highway. If you had no oil pressure at idle I suspect you'd also hear valvetrain noise.