Oil Pressure Problem - JeepForum.com
LinkBack Thread Tools
post #1 of 4 Old 08-26-2009, 09:21 AM Thread Starter
Registered User
1996 XJ Cherokee 
Join Date: Apr 2009
Location: Gaines, NY
Posts: 1,039
Oil Pressure Problem

ok so on my '96 XJ Sport 4.0L H.O. my oil pressure gauge is showing something strange.....it used to be at 0 when the engine was off then around 40 at an idle and go up a bit when i'm on the highway.....but recently the gauge has been saying 40 even when the engine is off (and has been off for a while) and says about 60 at an idle and goes up a little from there when I drive......

is it my gauge thats messed up or is it my oil pump or filter or what? is this a big problem?

'99 XJ Sport - The Green Lantern (sold) 4.0/AX-15/NP231/HP30/C8.25, 3" RC lift, 30's
'96 XJ Sport - The Red Zeppelin (DD) 4.0/AX-15/NP231/HP30/C8.25, 2" BB, IRO Front Hooks, Hella Black Magics

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

'91 XJ Briarwood - The Spruce Moose (Parting Out)
'79 J10 - Spartacus (Parting Out)
RedZeppelinXJ is offline  
Sponsored Links
post #2 of 4 Old 08-26-2009, 09:52 AM
Registered User
1997 XJ Cherokee 
Join Date: Aug 2009
Location: Marietta, GA
Posts: 343
Shouldn't all the gauges drop to zero when powered off ?

- _litz

1997 Jeep Cherokee Sport
1976 Fairmont MT-19
_litz is offline  
post #3 of 4 Old 08-27-2009, 06:03 AM
Registered User
1999 XJ Cherokee 
Join Date: Feb 2009
Location: ridgway pa
Posts: 146
there is an oil pressure sending unit that sends the signal to the guage. i would say that the unit is going bad. its buy the oil filter. i pretty sure thay are cheep and easy to fix.
xjhavens is offline  
post #4 of 4 Old 08-27-2009, 10:01 AM
It's the crank sensor!
tjwalker's Avatar
1999 XJ Cherokee 
Join Date: Nov 2007
Location: Central Minnesota
Posts: 8,847
Oil temp sending units are a very common failure on the Jeep 4.0 engine. And when they go south, they often exhibit the symptoms you are describing.

Some guys temporarily put a mechanical oil pressure gauge where the sending unit resides to verify their exact oil pressure, but my bet is that a new sending unit will restore your oil pressure reading accuracy. It is located directly above the oil filter.

You might want to try cleaning the electrical connector to the sensor with electrical contact cleaner first before replacing it.

I would highly recommend purchasing this directly from Jeep for best accuracy/mating with your factory gauge. Many people including me have had mixed (poor) luck with aftermarket hardware.

Good Luck!

99 Cherokee, 4.0 AW4, NP242
Past Jeeps: 49 Willys, 81 Scrambler, 88 Comanche
Without "data", all you have is an opinion!
tjwalker is offline  

Quick Reply

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
Oil Pressure Problem? TheIceMan XJ Cherokee Technical Forum 10 05-14-2015 06:27 PM
Oil Pressure problem? Livewire94 XJ Cherokee Technical Forum 24 08-06-2009 04:38 AM
Here we go again..ANOTHER Oil pressure problem Whtfairladyz XJ Cherokee Technical Forum 25 03-06-2009 01:10 PM
oil pressure problem Jayhawk077 XJ Cherokee Technical Forum 5 04-14-2006 09:09 AM
Oil pressure problem SpikeSpeigel XJ Cherokee Technical Forum 6 11-08-2003 04:18 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome