1994 Jaguar XJ6 oil pressure issue

jaguar
xj6

#1

I have a 1994 Jaguar XJ6 with 113,000 miles on it. Recently the oil light has been coming on and when below 15000 rpm the oil pressure gage drops to 0. So at idle speed or below I lose oil pressure. When ever I am able to raise the rpms the oil pressure gage returns to a normal reading. The engine oil is full. Am I losing my oil pump or what?


#2

It could be the oil pump, but is more likely worn engine bearings that don’t hold pressure when the oil heats up and thins. The first thing you need to do is take it somewhere and have the oil pressure checked with a mechanical gauge while the engine is hot. This will rule out a bad pressure sensor.

If you have worn bearings, you may still be able to run the engine for a long time before problems develop. It’s oil flow that lubricates the engine, not pressure, but you need pressure to get the oil to all the engine parts. The top half of the engine, the valve train, will suffer if the oil pressure is too low for too long. You may be able to prolong the engine’s life by going to a thicker oil–eg. if you use 5W-30, you can try 10W-30 or 40, as long as the manual allows the thicker oil.

Good luck.


#3

You might also consider that the redline for that engine is 5,000 RPM. If you have been running it at 15,000 RPM I’m surprised it didn’t blow up a long time ago.

sorry, I just had to.


#4

My mom’s old 94 XJ12 has the same problem. It’s the gauge not the engine most of the time. The sending unit is likely bad. Chalk it up to the Lucas electrics.