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jharrison13
03-08-2011, 06:40 PM
i am pretty sure i know the answer but i just want to check
my jeep when at idle the oil pressure is about 10, and when i am on the gas it is running normally at 40 but when i let off the gas it starts to go down. i assume i just need to change my oil pressure sending unit but i figured i would make a post and check with you guys.
rugidone
03-08-2011, 06:52 PM
Mine idles around 10 too, 30-40 when im on the throttle.
jharrison13
03-08-2011, 08:18 PM
so is that normal because i dont think mine has been doing that, i think mine has always been around 40 all the time i think., i havent noticed it moving around
rugidone
03-08-2011, 08:29 PM
book says min 13 psi at idle is standard and up 10 more psi per 1000rpms i think.
steph74
03-08-2011, 08:38 PM
what he just said....
(except I thought it was 16 ;))
jharrison13
03-08-2011, 09:05 PM
so do you guys think it would need a oil pressure sending unit?
modestmar00xj
03-08-2011, 10:11 PM
interesting cause im having kind of the same problem but when i start up the jeep sometime it says 0 and my engine light comes on and sometimes it says 30-40psi.
BrianXJ
03-08-2011, 10:32 PM
Well here is my delima. When me XJ is cold it runs about 20-30, when it gets to operating temp it drops to 0. I just changed my rear main and it is clean. new oil pump installed. I wonder what can be causing this?
Weldmen
03-08-2011, 11:26 PM
yer good. Nothing to worry about. :driving:
Mudderoy
03-09-2011, 05:57 AM
Well here is my delima. When me XJ is cold it runs about 20-30, when it gets to operating temp it drops to 0. I just changed my rear main and it is clean. new oil pump installed. I wonder what can be causing this?

I know it's just more money Brian, but you may want to invest in a mechanical oil gauge. Put it on there long enough to see what the REAL oil pressure is. What you are reporting doesn't sound right.
BrianXJ
03-09-2011, 12:02 PM
I know it's just more money Brian, but you may want to invest in a mechanical oil gauge. Put it on there long enough to see what the REAL oil pressure is. What you are reporting doesn't sound right.


I was thinking about that because a sender is $35 and a new gauge and sender aftermarket is only $18
Mudderoy
03-09-2011, 02:04 PM
I was thinking about that because a sender is $35 and a new gauge and sender aftermarket is only $18

Two things I always made sure I had on a rebuilt engine, mechanical water temp and oil pressure gauges.
jharrison13
03-09-2011, 06:07 PM
well the new sending unit fixed my problem whet and put it in this afternoon and made the oil pressure run normal again.
Switch_knuckles
03-09-2011, 11:50 PM
I have been having the same problem.
uberxj92
03-10-2011, 09:26 PM
i have a 4.7 stroker in my 92 xj & she runs about 12 psi at idle on fresh synthetic. tops about 60 psi. my renix 90 stays solid 20 -40 all of the time except when she gets hot in the mud. i use mech gauges. i think the stock gauges are guessing. but remember anything under 8psi & you are basically grinding metal. the worse thing is that the dummy lights trip at 8.5psi LOL
prerunner1982
03-10-2011, 11:17 PM
at idle mine is around 40psi or so and under throttle is upto about 60psi.
jharrison13
03-10-2011, 11:40 PM
that is what mine is now since i put the new sending unit in it
bluedragon436
03-11-2011, 10:54 AM
I like mine... it used to fluctuate a bit... till I replaced my valve cover gasket, did a good oil change and cleaned up the "PCV's"... now that thing runs like a champ, and hasn't dropped PSI at all while I'm driving...
BrianXJ
03-11-2011, 06:19 PM
put my mech gauge on mine. Runs around 40 psi when cold and right at 30 when hot. I say money well spent on the new oil pump and rear main
Mudderoy
03-11-2011, 11:09 PM
put my mech gauge on mine. Runs around 40 psi when cold and right at 30 when hot. I say money well spent on the new oil pump and rear main

Yep, sounds good. Now to fix the factory oil sender/gauge! :D
oderdene
03-11-2011, 11:29 PM
Are oil pressure and coolant temp gauges same? my oil pressure gauge is not working and I have spare temp gauge and guessing only difference is faceplate. Am I wrong?
Mudderoy
03-11-2011, 11:31 PM
Are oil pressure and coolant temp gauges same? my oil pressure gauge is not working and I have spare temp gauge and guessing only difference is faceplate. Am I wrong?

I don't know but from a factory perspective it sure does make sense. Cheaper just to buy one gauge and just use multiple face plates. I bet that's not the case though, makes too much sense! :D