jholden

Hello everyone! This is my first post. I have a question about my 2000 xj that I purchased about two weeks ago. The vehicle is solid and runs fantastic with one issue. The oil pressure gauge reads about 12 psi at all times. I changed the oil and no difference with a high viscosity oil. Any idea what to check now?

Ben Reilly

It's probably a bad oil pressure sender. It's cheap and easy to replace so you might as well change it and see if that fixes the issue.

extrashaky

It does sound like a bad sender, but...

Don't buy the cheap one from the local parts store. They're notorious for failing again and/or leaking prematurely. Some have been known to fail again within a couple of months. Instead, buy the expensive Mopar sender from the dealer parts department. It's usually worth paying extra to have a sender that actually works.

91 cherokeee

Sorry to hijack this thread (I'm new and couldn't figure out how to start a post)... my oil pressure is 60 psi at start.. a little background 4.0 inline 6 with 270,000 miles. I've had it for ten years and it always ran a little above 40 on the freeway... I put the 165 f stat a few years back and I guess it stuck open so it was running pretty cool for a few years.. I just changed the stat back to a 195f.. but what's odd is the hihigher temp doesn't bring down the oil pressure.. the pressure appears to reduce from driving. On the freeway at 55mph it will get to 75+ to nearly 80. Today while on the freewayy I floored it while it was at 75 and it actually dropped to 60 for a few minutes and tgen went back up to 75 only to drop to 60 aafter driving for twenty minutes.. at idol once it regulates it ranges from 24 to 20. In town it can climb to 75 from a stoplight accelerating to 35mph.. I've changed out the sending unit and put a mechanical gauge on it and it is high.. I plan on changing the oil pump because from what I've read nothing else causes or regulates oil pressure. Does anyone know if the oil pump can regulate the oil beyond a 75 emergency valve opening? When my pressure does go down it "brups" often dropping 20 psi at a time.. oddly it's driving, not the operating temperature that causes the drop. I got a melling m167hvs pump but I did read somewhere that you need a special tool to attach the the pickup tube (that came with the pump). Also I have run 5 oz of seafoam and currently have one qt of mystery oil in the crank case....

TFitzPat87

For the last poster, just so you know, the pump doesn't regulate oil pressure. The gaps in between bearings and such is what regulates pressure.

Also, to the OP, I would suspect the sensor as well.