oil pressure - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Cherokee & Comanche Forums > XJ Cherokee Technical Forum > oil pressure

Introducing MONSTALINER™ UV Permanent DIY Roll On Bed LineThe Solution to Radius Arm Bind - Meet Lock-N-LoadFS: Jeep Fog Light LED Bulbs! Several Brightness Options!

Reply
Unread 07-03-2013, 07:11 PM   #1
josh1011
Registered User
1991  
 
Join Date: Nov 2012
Location: frankford, delaware
Posts: 15
oil pressure

What is normal oil pressure for the 4.0 with 87 octane and 200k miles

josh1011 is offline   Reply With Quote Quick reply to this message
Unread 07-03-2013, 09:44 PM   #2
BIGBADWOLF
Registered User
2004 WJ 
 
Join Date: Aug 2012
Location: Charlotte, North Carolina
Posts: 439
Depends on how much wear in the engine. Pressure is not a function, it is an indication of engine condition.
BIGBADWOLF is offline   Reply With Quote Quick reply to this message
Unread 07-03-2013, 09:45 PM   #3
cruiser54
Web Wheeler
 
cruiser54's Avatar
1990 MJ Comanche 
 
Join Date: Oct 2009
Location: Prescott, Arizona
Posts: 10,160
Quote:
Originally Posted by josh1011 View Post
What is normal oil pressure for the 4.0 with 87 octane and 200k miles
What's yours?

And BTW, octane rating of gasoline is in no way relative to oil pressure.
__________________
Quote:
Originally Posted by chris87xj View Post
If you own a Renix Jeep, you'll want to check this out. >

An index to over 25 write-ups can be found in Post #1.

Cruiser's Mostly Renix Tips
My Jeep Technical Photos

http://www.cherokeeforum.com/g/album/1725214
cruiser54 is offline   Reply With Quote Quick reply to this message
Unread 07-07-2013, 08:43 PM   #4
rmockelman
Registered User
1993 XJ Cherokee 
 
Join Date: May 2005
Location: Omaha, NE, Nebraska
Posts: 26
My 93 at a warm upped idle is at 35. Normal driving is around 50
__________________
1990 Cherokee Laredo 2Dr
Stock for now
rmockelman is offline   Reply With Quote Quick reply to this message
Unread 07-07-2013, 11:03 PM   #5
Hudson
Registered User
1999 XJ Cherokee 
 
Join Date: Mar 2010
Location: New Milford, Connecticut
Posts: 785
The oil pressure spec. for the 4.0 is this:

*Not less than 13 psi at HOT idle
*Between 37-75 psi OVER 1600 rpms
__________________
Live To Die. You're Not Going To Get Out Of This One Alive.

Build Thread - http://www.ausjeepoffroad.com/forum/showthread.php?t=121903
Hudson is offline   Reply With Quote Quick reply to this message
Unread 07-08-2013, 09:38 AM   #6
brettgorringe
Registered User
2001 XJ Cherokee 
 
Join Date: Jul 2013
Location: tooele, ut
Posts: 45
I have a 2001 Cherokee and my oil pressure reads about 40 when cold and slowly down to zero when it'd warmed up. But it still runs perfectly fine cold or hot. I replaced the oil pressure sending unit and the oil pump and I don't know what els would cause that. If anyone could help me please? The pressure goes up to 10 or 20 when acceleration but when I am just cruising it drops to zero again
brettgorringe is offline   Reply With Quote Quick reply to this message
Unread 07-08-2013, 03:49 PM   #7
playbass
Registered User
1998 XJ Cherokee 
 
Join Date: Mar 2013
Location: Salt Lake City, Utah
Posts: 34
Quote:
Originally Posted by brettgorringe View Post
I have a 2001 Cherokee and my oil pressure reads about 40 when cold and slowly down to zero when it'd warmed up. But it still runs perfectly fine cold or hot. I replaced the oil pressure sending unit and the oil pump and I don't know what els would cause that. If anyone could help me please? The pressure goes up to 10 or 20 when acceleration but when I am just cruising it drops to zero again
Your bearings may be shot and the clearances are too big causing low oil pressure in your engine. Have you ever had coolant mix with your oil? Coolant eats bearings really quickly.
playbass is offline   Reply With Quote Quick reply to this message
Unread 07-08-2013, 03:53 PM   #8
brettgorringe
Registered User
2001 XJ Cherokee 
 
Join Date: Jul 2013
Location: tooele, ut
Posts: 45
I just bought it about a week ago and I have not changed the oil yet. How do know if any has got into the bearings? And what bearing are you talking about
brettgorringe is offline   Reply With Quote Quick reply to this message
Unread 07-08-2013, 03:57 PM   #9
brettgorringe
Registered User
2001 XJ Cherokee 
 
Join Date: Jul 2013
Location: tooele, ut
Posts: 45
and also it has a hard time accelorating after like 65 mph itll go faster if you floor it but it wont keep up the fast speed without keeping on the gas real hard and rapping out the engine.
brettgorringe is offline   Reply With Quote Quick reply to this message
Unread 07-08-2013, 04:08 PM   #10
playbass
Registered User
1998 XJ Cherokee 
 
Join Date: Mar 2013
Location: Salt Lake City, Utah
Posts: 34
Quote:
Originally Posted by brettgorringe View Post
I just bought it about a week ago and I have not changed the oil yet. How do know if any has got into the bearings? And what bearing are you talking about
Apologies, I did skip a few steps. If you just purchased it, I would change the oil and filter immediately. Make sure you put a decent filter on there, like Wix or Mopar.

If you still have low oil pressure, you need to check it with a mechanical gauge to verify what you are reading on the gauge is correct. Oil Pressure Sending units go bad often enough.

Next, if you still have low oil pressure, you need to take a look at the main bearings, you may have damage to them caused possibly by coolant mixing with your oil. The 00-01 models have a bad head that cracks more often than the other years allowing coolant to mix with oil.
playbass is offline   Reply With Quote Quick reply to this message
Unread 07-08-2013, 05:08 PM   #11
brettgorringe
Registered User
2001 XJ Cherokee 
 
Join Date: Jul 2013
Location: tooele, ut
Posts: 45
Thanks for your help but I still have a couple questions. the head is new so where are the mmain bearings loacated and are they cheap and easy to replace?
brettgorringe is offline   Reply With Quote Quick reply to this message
Unread 07-08-2013, 05:19 PM   #12
playbass
Registered User
1998 XJ Cherokee 
 
Join Date: Mar 2013
Location: Salt Lake City, Utah
Posts: 34
Quote:
Originally Posted by brettgorringe View Post
Thanks for your help but I still have a couple questions. the head is new so where are the mmain bearings loacated and are they cheap and easy to replace?
Check the other things I listed first before the bearings. This site has a lot of information on what to do next if you rule out the oil filter and oil pressure sending unit.

I've never done a bearing job, so I can't speak about how easy/hard it is.
playbass is offline   Reply With Quote Quick reply to this message
Unread 07-08-2013, 06:00 PM   #13
brettgorringe
Registered User
2001 XJ Cherokee 
 
Join Date: Jul 2013
Location: tooele, ut
Posts: 45
I'm new to thus site sorry this is my first thread. How do I find more info on the bearings? I just replaced the sending unit and did a oil change. Still funny pressure. I'm wondering if maybe I should sell it to someone who knows what they are doing or could I do it cause I really like this jeep its way nice.
brettgorringe is offline   Reply With Quote Quick reply to this message
Unread 07-08-2013, 08:53 PM   #14
BIGBADWOLF
Registered User
2004 WJ 
 
Join Date: Aug 2012
Location: Charlotte, North Carolina
Posts: 439
Quote:
Originally Posted by brettgorringe View Post
I have a 2001 Cherokee and my oil pressure reads about 40 when cold and slowly down to zero when it'd warmed up. But it still runs perfectly fine cold or hot. I replaced the oil pressure sending unit and the oil pump and I don't know what els would cause that. If anyone could help me please? The pressure goes up to 10 or 20 when acceleration but when I am just cruising it drops to zero again
If it is running fine I would not worry about it unless it starts knocking. There have been MANY 4.0s that have ran a long,long time with low oil pressure.
BIGBADWOLF is offline   Reply With Quote Quick reply to this message
Unread 07-08-2013, 09:12 PM   #15
playbass
Registered User
1998 XJ Cherokee 
 
Join Date: Mar 2013
Location: Salt Lake City, Utah
Posts: 34
Quote:
Originally Posted by BIGBADWOLF View Post

If it is running fine I would not worry about it unless it starts knocking. There have been MANY 4.0s that have ran a long,long time with low oil pressure.
This is true, too. While technically your engine is out of spec if you have 0 psi there are a lot of 4.0s out there running with the same issue.
playbass is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

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:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

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.


Thread Tools






Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.