Just noticed that my oil pressure gauge is low.

I started getting today a 'check gauges' red warning when starting the engine, then it goes away and the indicator goes slowly up to 5. Sometimes climbs up to 10 when driving, and drops back to 5.

I clearly remember the pressure gauge going up and down together with engine RPM and sometimes all the way to 40. Never was below 10 at idle.

This is a car with only 60K that has been really well maintained. Last oil change was 2K ago (Mobil1) and no issues afterwards and no work on the engine.

Couple questions:
Where does the gauge get the reading from and could that unit be having issues? Is it an issue to replace?

If the oil pump is toast, what does it take to replace? Does the oil pan come neatly off or do I need to take a bunch of things out to clear it?

Thanks.

 

The first thing you need to do is verify the oil pressure. You can barrow a mechanical oil pressure gauge from any auto parts store. You need to connect it at your pressure sending unit. Which is located right next to the oil pressure. It can be as simple as replacing your pressure sending unit.

 

Always good to do. The gauges on the XJ aren't known to be 100% accurate.

Also, what kind of oil filter are you running? Any engine ticks or knocks?

 

I had a similar problem and was planning to do a mechanical gauge check. Then once while the hood was up I was spotting the location of the oil pressure sending unit and did a visual inspection of the connection. While checking it I wiggled the wires and suddenly my oil pressure reads normal all the time. Still plan the mechanical gauge check but feel better about my oil pressure.