VFQuake

Okay, typically my oil pressure is (Idle: 60, driving 80).

I wheeled harder than normal today (spent a lot of time in 4low climbing), and now my XJ is idling at 20, and peaking at 60, is something wrong here? It drove the 10 miles home just fine, felt a little different than normal, but I think that's because I spent so much time on the trails, that driving on smooth road was weird..

Any ideas on what would be causing this?

RTorrez1

First thing you should do is verify the oil pressure with a mechanical pressure gauge and connect it to where the oil pressure sending unit is connected. Then we can go from there.

Bustedback

Congratulations, you're the only XJ owner to ever see 60psi of oil pressure at idle.

RTorrez1

Yeah, That's why I said to verify the pressure. It was probably reading wrong before and after running her hard it may have knocked some of the crud out of the sending unit and made it read right.

VFQuake

I had it checked with a guage prior to this "issue", and it was accurate.

I figured it out though, it was low because of the oil being nice and warm. I let it cool off for a few hours, and it was back to normal. I've never wheeled it for that long before, so I had never had the oil at full temp, I'm assuming.

cruiser54

That's sky-high oil pressure. Not normal at all. The readings you got after wheeling are in line with good oil pressure. What brand of oil filter are you using?

VFQuake

It's not sky high, and I'm using a K&N filter. Changed regularly. I have a high volume pump.

HS00XJ

mine idles at 40 and runs at 45.is 60 and 80 not high?

VFQuake

It's not uncommon for 60-70 when driving, for a lot of XJ's, with stock pumps. 60-80 for me, with a high volume pump, isn't bad at all.

cruiser54

I have a high volume pump in 2 of my Xjs and see the 45 to 60 range. YOURS is not common, but if you like it that's all good.

Having been a Service Manager and Shop Foreman at a Jeep dealer from 1980 through 1992, I've seen more that a few XJs with 4.0s. 60 to 80 usually signified a bad oil sender or a restrictive oil filter.

VFQuake

Well, everything on my end, mechanically, is fine. Pump is good, sender is good, had the same pressure prior to changing my oil and filter. Startup at 1100 rpms, drops to 900 shortly after, temp never exceeds 210. Jeep runs like a top, and if you'll read around at other threads, it's not uncommon for "driving down the road" to be at 70 psi.

Regardless, I appreciate your input, and that you actually took the time to read my post.

bigbadon

Agree. High pressure simply means oil is dead heading and not freely flowing. Excessive pressure is unnecessary and contributes nothing to the reliability of an engine.

VFQuake

My XJ seems to run noticeably "perkier" when the pressure is where it normally is. When it was running 40-60, it honestly seemed to run kind of crappy. (in comparison).

cruiser54

Well, I do read alot of threads. And the ones that mention high oil pressure like that have wonky senders. I've driven hundreds if not thousands of Jeeps with 4.0s and at road speed they read about 2 needle widths above the center line of the gauge. Just clarifying. I'm glad you like the gauge reading you've got.

cruiser54

That makes no sense at all. The amount of oil pressure has nothing to do with engine performance, except when there is none, and the motor seizes.