Low oil pressure on a 258 - Page 2 - JeepForum.com
LinkBack Thread Tools
post #16 of 23 Old 11-15-2013, 10:35 AM
Registered User
Join Date: Nov 2013
Posts: 1
i had the same problem, no to low oil psi. on newly rebuilt, found i had forgoten to put the front oil galley plug in. got oil to lifters but no higher. plug in psi good

johnnykind likes this.
157jeep is offline  
Sponsored Links
post #17 of 23 Old 08-06-2016, 08:56 AM
Registered User
Join Date: Aug 2016
Posts: 1
I have a 1980 J10 which has 12,000mi on the rebuild. It ran 40-60 consistently until a few weeks ago. It now still runs 40-60psi cold and then drops to 20 when it warms up and then under load or on the highway (2000-3000rpms) it drops down to 15psi. As soon as I pull over and let it idle the pressure comes back up to 25-30psi. Any ideas? I don't believe the oil pump or pressure regulator valve were replaced in the rebuild but it has run good oil pressure until lately. The guys at my local mechanic shop said "No worries. Anything above 3psi is 'oil pressure' and that's all you need to keep running it." I am nervous about the new lack of consistency in oil pressure so I'm going to get a couple more opinions. I also own a jeep cherokee (1995) which has 235K on the Chrysler I6 and still runs consistent 40-60psi no matter the temp or how hard the engine is working. While I realize two totally different engines I'm not used to seeing that low oil pressure and after spending the money to rebuild the engine in the J10 I don't want to ruin it, so, I'm going to keep checking with folks. Any input folks might have on here would be appreciated. The oddest part of this for me is that the oil pressure stopped being consistent after about 11-12K miles on the rebuild and now runs higher oil pressure at warm idle than running down the highway at 3,000rpms warm. I HAVE replaced the sending unit and tested the wires from the sending unit to the instrument panel and gauges. That all checks out! Thanks!
MTJeepGuy is offline  
post #18 of 23 Old 08-06-2016, 09:55 AM
Registered User
1984 CJ8 
Join Date: Jun 2013
Location: Denver
Posts: 1,508
Could be sign of an engine problem. Or it could be a screwy gauge/sending unit/wiring. I'd verify the pressure reading with another gauge (preferably a good mechanical gauge).

When I was younger, I thought I was Don Quixote... turns out I'm just another donkey-hootie.
Spieg8 is offline  
post #19 of 23 Old 08-06-2016, 11:32 AM
Registered User
1985 CJ7 
Join Date: Jul 2010
Location: The Mojave Desert - Palmdale, Ca. U.S.A.
Posts: 6,702

NEVER trust OEM Jeep oil psi, ele gauges.
If you really had the low psi the gauges sez you do. Your lifters would be 'talking' to you.

Have'n you along, is like loose'n 2 good men
LumpyGrits is offline  
post #20 of 23 Old 08-06-2016, 12:13 PM
Registered User
1977 CJ7 
Join Date: Mar 2011
Posts: 4,042
Originally Posted by LumpyGrits View Post
NEVER trust OEM Jeep oil psi, ele gauges.
If you really had the low psi the gauges sez you do. Your lifters would be 'talking' to you.
I agree. Also, it's possible to get the wrong oil pressure sender for the OEM gauge. There were two styles and the wrong sender could scare the daylights out of you.

A sender giving you 68 ohms means 60lbs of pressure with one gauge, and 0 with the other. Verify first, then panic.

I'd rather be lost on the trails than found at home!

Phoenix Rising- A Flame Off Restoration?
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
WindKnot is offline  
post #21 of 23 Old 08-06-2016, 01:05 PM
Registered User
1985 CJ7 
Join Date: Jul 2010
Location: The Mojave Desert - Palmdale, Ca. U.S.A.
Posts: 6,702

Even IF you have the correct 'sender'. It could very well be the gauge that's TU.
Also-A lot of these gauge issues can be traced to bad GND on the dash panel. Run a dedicated lead from the dash panel to the battery NEG(-).

Have'n you along, is like loose'n 2 good men
LumpyGrits is offline  
post #22 of 23 Old 08-07-2016, 08:37 AM
Jeep. There's Only One
keith460's Avatar
1984 CJ7 
Join Date: Jan 2007
Location: Doylestown, PA
Posts: 7,041
I had a similar problem with my rebuilt engine where the oil pressure would drop after reaching operating temperature. Found the problem being the new oil pump, Meling, was not machined flat like the original and required a gasket under the mounting surface. The original did not have one so I installed the new one without one too. That turned out to be the problem and had to drop the oil pan, remove the pump and install a gasket for the pump-to-block mounting surfaces. Cured my issue and now oil pressure is at 60psi when cold starting and then settles to about 20psi once things warm up.

1984 CJ-7 Renegade
keith460 is offline  
post #23 of 23 Old 08-07-2016, 12:59 PM
Registered User
1988 YJ Wrangler 
Join Date: Mar 2011
Location: Lucerne Valley
Posts: 56
Red face low oil pressure

Originally Posted by 81cj7id View Post
I have a 1981 Jeep cj7. It has the 258 which was recently rebuilt. The problem is it only holds about ten pounds of oil pressure at idle. Is this right? A brand new oil pump was installed when it was rebuilt. I also get a tapping noise that sounds like valves/lifters. Any ideas? Thanks.
Had the same thing here is what happened to me, during the engine rebuild we missed a plug under the timing cover, I believe it was a 3/8 plug Allan head type...
everyone of those plugs that come in the rebuild kit have to go somewhere if you have some left over Figure out where they need to go !!!@

had low oil pressure for a week talked to all my mechanic buddys, put in a new high volume oil pump, still low pressure, did not want to blow up the new engine so we pulled the whole thing back out and started to take it back apart piece by piece till we found the hole for the missing plug put it back together, worked perfect !!!

Your problem may be different but that is what caused my low oil pressure, all the oil was going to the timing cover and not to the rest of the engine,
If your oil pump is working, and your GAUGE is working too, and you don't have any blocked passageways... try checking under the timing cover and make sure the correct plugs are in there...
johnnykind 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 help socalflofam Jeep CJ Forum 6 07-22-2010 02:39 PM
Cj5 oil pressure SQF1 Jeep CJ Forum 7 04-01-2009 01:58 PM
no oil pressure 77cj5sea Jeep CJ Forum 5 01-01-2009 10:09 AM
Oil Pressure ctsymonds Jeep CJ Forum 10 02-22-2006 01:51 PM
NO Oil Pressure!!! jeepthng Jeep CJ Forum 4 11-08-2005 09:15 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