wildbill1

My daughter drives a 2000 GC with a 4.0. She has owned it for almost 2 years and it has been very reliable and trouble free. It has about 125,000 miles on it.

She called me yesterday and told me that her "check gauges" light was coming on and the oil pressure was going near 0 when idling. I told her to pull over somewhere right away and check her oil level. She called me back a couple minutes later and said the oil level was actually a little over full.

Since she wasn't far away, I jumped in my XJ and went to where she was parked. Sure enough, the oil level was about 1/8" over the full mark on the dipstick. She is getting near 3000 miles on the oil that's in the Jeep and is due for an oil change soon. The GC has never used any oil between changes and she tells me that she checks it fairly often, whatever that means. The oil pressure comes up right away as RPM increases. At 1500 RPM, the oil pressure gauge is reading over 40 psi. The engine is running smooth and isn't making any unusual noise.

The oil isn't really dirty but seemed a little thin and there was no evidence of coolant either on the stick or on the oil fill cap or inside the valve cover. The coolant level is fine and there's no evidence of oil in the radiator.

I told her to minimize her driving until she can get the oil changed. I hope after a change the problem goes away, but of course, I'm concerned. Anybody have any ideas why the pressure would drop so low at idle? Should I be planning on replacing an oil pump soon?

wildbill1

I got to thinking about this issue a little more and remembered that my wife's old truck, a '96 Ram pick-up, once showed low oil pressure suddenly. I swapped out the oil pressure sending unit and the problem was solved. I just picked up a sending unit for the GC and have my fingers crossed.

Ender

Alright, let us know if that fixed the problem! Good Luck.

SteelBlue99

Had the same issue with my old WJ. Changed the sending unit, and everything was fine. Hopefully that solves your problem too!

jeff2285

my xj does the same thing has 130,000kms it goes down to the 1st tick when idiling, probably the oil pump

wildbill1

I just changed the sending unit and we're back to normal!! I'm probably happier than my daughter. I really didn't want to have to change the oil pump.