I have a 03 Jeep Wrangler Rubicon with the 4.0 motor.
I started it this morning and the oil pressure gauge did not move.
After a few seconds the check gauges light came on and I saw there was no oil pressure, the jeep was running smooth and sounded fine.
I shut the jeep off and checked the oil and it was ok, so I started it again and the light came on again.
I waited for a little bit and tried it again this time the gauge moved but when it did it was jerky. The gauge went over half way and stopped where it normally does but it did not sweep smoothly.
I shut the jeep off and tried it again and the gauge was moving but it was jerky. I made a few trips today and the jeep ran fine except for when you start it and the oil pressure has to build up and the gauge is jerky
Do I have a bad gauge?
Is my oil pump going out?
Has anyone else had this problem?
Only way to be sure is to hook a mechanical gauge to the engine and test it. If the oil pressure is fine on the mechanical gauge, then it's probably the sender, wiring or gauge, but the sender is typically what fails.
'06 Rubicon Unlimited Sienna Jeep Club: Member #15
I'm a career submarine sailor who navigated the world blind excect for instruments, where I learned the sacred law 'never doubt your instruments'.....but in this case and how you described the failure mode, I would first suspect all suggest above.
Till then, drive it and listen for clacking lifters when you doubt....the top end gets oil last, so it will talk to you.
I had/still have the same issue in my 97 TJ. Replaced sending unit and gauge would still drop. Put in a mechanical sending unit...pressure was rock solid. Finally discovered it was the instrument cluster wiring harness connection. Greased it up and put it back together and the gauge worked for a couple years and now it's jacked up again.
...the sacred law 'never doubt your instruments...
I drove a '50 Chevy truck for over 20 years that didn't have a working speedometer, odometer, or fuel guage. Never got a speeding ticket, and yes, it was capable of speeding. The only time I ran out of fuel was when my wife drove it and didn't tell me.
Keep in mind that free advice can frequently be worth less than you pay for it.
Which unfortunately isn't considered by many as a quality/reliable replacement sender. It took me three trips to Autozone one Sunday when the dealer was closed to finally get an oil pressure sender that worked properly. OE senders/sensors are the only ones I can recommend, most of Autozone's come from China.