91 W250 low oil psi

[greenallgreg]

My low oil psi light is coming on after the oil gets up to operating temp. I have good oil psi on start up (50-60lbs) and while driving (50lbs) but once I come to a stop it drops around 23-24psi and trips the light on the dash. The truck had a mechanical gauge when I bought so I just left it as the factory gauge is all over the place. Could this possibly be caused by my idle being too low or is a bad oil pump possibly the culprit?

 

[AH64ID]

Your mechanical gauge is likely correct as those numbers look appropriate.

So I’d say the OEM sender is shot, and needs replaced.

 

[cerberusiam]

The factory sensor is notorious for not working correctly. Do you have the mechanical gauge tapped to the same place as the factory sensor?

 

[greenallgreg]

The factory sensor is notorious for not working correctly. Do you have the mechanical gauge tapped to the same place as the factory sensor?

Yes the gauge is tapped into the oil pressure switch on the side of the block.

 

[ofelas]

Sounds like the oil pressure sender.

Cummins 3923200 or Mopar 53030493 with the appropriate deep well socket will work.

 

[greenallgreg]

I replaced the sender with one from Cummins and so far so good! Thanks everyone for your help!