I know there are TONS of oil pressure post on here, none that I can find that have all of my syptoms. So here we go.

1997 xj 4.0L 140,xxx 5w-30

Cold start up pressure is 40
Cold no load rev engine pressure is 40
cold take off from stop sign pressure drops as rpm go up

hot start up 0 until rev engine
hot idle 10psi
hot no load rev 10 up to 40
hot take off from stop light 10 up to 40

I have not verified with mechanical gauge (no one rents them here) and with it going up in pressure when its hot and down in pressure when its cold makes me think the sender is ok.
I have tested the gauge it is good.
The only other thing is that the pan looks like it has been bent from the p.o. dont know if it hit the oil pump, that will be checked with the next oil change

Any idea or help would be great

 

Try changing the o rings where the oil filter screws on I think its a t60 torx bit you'll see an improvement in oil pressure or you spun a bearing when you pull the oil pan pull a rod and a main cap if you see a copper color your bearings are junk and you'll probably need the crank micro polished if its real bad I had my crank done it was like 40 bucks and the the bearings are like 70 to 80 total best money I ever spent

 

Must verify. No other way to determine root cause.

Beg, borrow or steal a mechanical gauge.

Anything less is guesswork.

 

Pay somebody to check it if you have to.

 

sounds like when my cam bearings went out. But i would have the pressure checked before you do anything. I also wouldn't wait untill your next oil change to pull the pan and look att he pump, if the pick up was bent and is starving the engine of oil you may not have the time to wait. depending on where its bent...

 

I had a similar problem in my 1999 jeep xj. After looking through my Haynes manual I seen that above the oil filter is a sensor which I believe was about 30 dollars at the local parts store. No promises but it was the easiest fix for me without doing alot of other work.

 

Thanks for the advice everybody.

 

Def don't go dicking with that O ring right off the bat. That is a PITA and I doubt that helps.

My bet is on the 30 dollar sensor mentioned.

If not that I say oil pump.

 

Yeah I don't think it's the adapter but it is leaking so that will be on the list while I'm at it.