mcnerd

1989 4.0l Renix. Only modification is Bosch 4 hole injectors.

According to the FSM idle 600 RPM oil pressure should be 13 psi. Above 1600 RPM 37-75 PSI

I basically sit at about 50 all the time including idle. It does idle a little fast but not over 1000 RPM's and at times it will idle closer to 600 but oil pressure is NEVER below 40.

Should I be concerned?

If I should be concerned any suggestions on where to start?

Cummins93

Crosscheck the pressure with a known good mechanical gauge.

mcnerd

Will do. Thanks for the suggestion.

If the guage is accurate should I be concerned? Lots on the to do list so trying to prioritize what to focus on.

Thanks in advance.

gat

You might be able to search the internet to find a table of Ohms (resistances) and gauge readings. Unplug the connector from the oil pressure sending unit. Did your gauge move? You can connect resistors to test the gauge by viewing corresponding values on the gauge or not

cruiser54

mcnerd

Update on this with some questions.....

I am working on getting my hands on an oil pressure gauge. The information provided so far has been very helpful.

In the mean time I gave it an oil change and new filter last night hoping that might bring it down. No change. First oil change I have given this XJ. I used 10w-30 syn blend with a wix oil filter.

I have also been watching the oil pressure very carefully over the last week. It defiantly drops significantly after warming up.

Question 1. If I pull the oil pressure sending uniy to bench test it is it safe to assume that I will lose a significant amount of oil?

Question 2. Should I be freaking out and parking the XJ until I know exactly what is going on. It runs great and stays cool, so I would normally not be too concerned, but I also do not want to destroy the engine. Opinions?

Question 3. If it is high pressure what is most likely the cause based on your guys experiences?

TIA.

cruiser54

Oil loss is negligible.

Quit worrying about it. Don't park it.

Probably just a faulty sender anyway.