bmrrwolfe

Well I haven't driven the XJ in a week or so, so I figured I would take it out today. I go out let it warm up for 5 mins and head over to a friends house. Just a few miles away and at a stop light I saw the check gauge light come on, and notice the oil pressure almost down to 0.. I hit the gas and it went up to 20ish.. the last mile or so there it stayed right around 25..
No unusual sounds, the oil level is exactly at the top of the safe mark, and no known leaks going on.
It has always sat right about 50 when driving, and for the first few miles I think was still right about at that level.

I have only put about 150 miles on the XJ since I got it from my dad who put in a JY motor with under 100k on it, and the oil was changed when the motor went in, so its still fresh.
I'm going to be safe and change the oil and filter first to see if that can help at all, but not till tomorrow afternoon or Friday when its above 20 degrees...

What could be the problem? Bad gauge? Oil pump? Something else?

I am afraid to even drive it home so I left it there for the night..
Thanks for any help!

bmrrwolfe

Anyone??

HCCAFan

People always claim it's the guage (read denial). In my experience, it was the oil pump.

Bustedback

Replace the oil sending unit BEFORE ripping into the engine or replacing the gauge. While you have the sending unit out, check the oil pressure with a mechanical gauge and see what it is really. The factory gauge has a built in fudge factor and is not as accurate as a mechanical gauge. Rule of thumb is 10psi of oil pressure for every 1000rpm.

bmrrwolfe

Well I think shes fixed!
I got a chance to look under the hood at the sending unit and found the wire not clipped in or tight... Well I took it off cleaned it up and plug it in tight (i think the clip that holds it in is broken as it doesn't lock in place) but started it up and pressure is back at 40 and let it run 5-7 mins to almost normal temp and it stayed put!

HCCAFan

Nice.

bmrrwolfe

Well drove to work with it (only a few miles) and got up to operating temp, and still stayed between 40-50 the whole time driving. At an idle it dropped to 30-35, but I believe thats exactly how it always was.

Wiring still doesn't click and hold into place, so I will need to find a way for it stay snug into the harness..