Oil Pressure Drops Intermittently - 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 Drops Intermittently

Rough Country Lift Kits and Parts!Dan's Old as Dirt Birthday Sale!Premium LED Lighting by VISION X, Proudly sold at ROCKRIDG

Reply
Unread 03-12-2012, 12:56 PM   #1
whitetrash
Registered User
1997 XJ Cherokee 
 
Join Date: Nov 2011
Location: Watertown, MA
Posts: 25
Oil Pressure Drops Intermittently

Intermittently, my oil pressure gauge drops, then comes back up. Lately, it's been happening more frequently, and it often goes all the way to zero, and the check gauges light comes on. Any troubleshooting tips? What might be causing this problem? Thanks!

whitetrash is offline   Reply With Quote
Unread 03-12-2012, 01:10 PM   #2
DerMeister
Registered User
2000 XJ Cherokee 
 
Join Date: Apr 2010
Location: MI
Posts: 768
Need more info...oil pressure while at speed and at idle?

Have you changed the oil latley?

Weight and filter brand?

Any overheating problems?

Year?
DerMeister is offline   Reply With Quote
Unread 03-12-2012, 04:20 PM   #3
whitetrash
Registered User
1997 XJ Cherokee 
 
Join Date: Nov 2011
Location: Watertown, MA
Posts: 25
It's a 1997 XJ, 4.0L with about 121k miles. Manual transmission, if that matters. It never overheats... temp is always perfect. New thermostat and water pump less than 2 years ago. I have changed the oil recently (less than 2k miles ago). I always use 10w30. I used a Bosch Premium filter, 'cause I hear they're made by Purolator now (used to use FRAM, 'til I realized how lousy they are). I replaced the oil filter adapter O-rings at the time, and also put on a nice new Felpro valve cover gasket. I'd been losing about 1 qt. of oil every 500 or so miles. After that I went about 1000 miles before I found myself running 1 qt. low. I've never seen any oil drip on the ground, even when I park it for a while. I don't think I'm burning much, either. I've got the usual blow by crud on top of the valve cover, but I don't see how that would account for losing over a quart. Right after oil change, the oil pressure was 40 psi at throttle, and 30-35 at idle. Now it's generally 20-30 at throttle and 10 at idle.
whitetrash is offline   Reply With Quote
Unread 03-12-2012, 04:23 PM   #4
whitetrash
Registered User
1997 XJ Cherokee 
 
Join Date: Nov 2011
Location: Watertown, MA
Posts: 25
Also, my belt's been squealing, and periodically my voltage drops to nothing and the gauges light comes on. Could this be related?
whitetrash is offline   Reply With Quote
Unread 03-12-2012, 04:40 PM   #5
tjwalker
It's the crank sensor!
 
tjwalker's Avatar
1999 XJ Cherokee 
 
Join Date: Nov 2007
Location: Central Minnesota, MN
Posts: 8,408
1. Oil pressure sending units are a common failure. You could try a new one. If you do so, buy it directly from Jeep for the best reliability/accuracy/mating with your factory gauge.

2. The belt squealing/voltage drop is most likely a belt that is not tensioned (tightened) properly. Remember that the serpentine belt is powering your alternator. Start by inspecting the belt. Just replace it if it has over 60k on it. Goodyear Gatorback is a good replacement. The belt on the 4.0 needs to be pretty darn tight to stay quiet.
__________________
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   Reply With Quote
Unread 03-12-2012, 04:47 PM   #6
michaelleegarre
Registered User
2000 TJ Wrangler 
 
Join Date: Jun 2009
Location: kentucky
Posts: 184
Try the oil pressure sending unit mine was acting up so i went and bought a universal oil pressure gauge and checked it came out to be a bad sending unit
__________________
Michael Garrett
1987 YJ - sold, 1995 ZJ - sold, 1998 XJ - sold, 2000 TJ
michaelleegarre is offline   Reply With Quote
Unread 03-12-2012, 05:19 PM   #7
DerMeister
Registered User
2000 XJ Cherokee 
 
Join Date: Apr 2010
Location: MI
Posts: 768
Quote:
Originally Posted by tjwalker
1. Oil pressure sending units are a common failure. You could try a new one. If you do so, buy it directly from Jeep for the best reliability/accuracy/mating with your factory gauge.
My thoughts too. Id start here.
DerMeister is offline   Reply With Quote
Unread 03-20-2012, 08:47 AM   #8
CJRex0110
Registered User
1986 CJ7 
 
Join Date: Oct 2011
Location: Jacksonville, Fl
Posts: 14
Had anyone had luck with this fix??

I have a similar issue and could use some help...

I have a 95 4.0 with fairly low miles. My jeep is more of a toy and not a daily driver. I noticed when it sits for a few days not more than a week that once it start it up the voltage and oil pressure are low. Sometimes when I drive a few miles both come back up and and all is good. Othe times it takes a few stops and restarts before it straightens out. If you drive at speeds above 50 the pressure gets lower and eventually the light comes on.

It almost seems backwards... When you sit at idle the pressure rises but when you take off the pressure drops the faster you go the lower the pressure gets on the guage. I replaced the gauge about 3 months ago and this issue just started a couple weeks ago.

Could it be the pressure sensor going bad? Would oil and voltage correlate to each other? Why does everything straighten out at the same time?

I notice that when the issue is occurring the the voltage drops lower and lower as you turn on the fan or headlights or anything that draws power...

The alternator is new and the oil has been changed fairly recent and still looks good. The jeep always seems to drive fine and has plenty of power even when the light comes on. Once you stop turn off the engine and restart the light is off and sometimes fixes the issue for a few miles or even a few days.?.?. Any ideas??
CJRex0110 is offline   Reply With Quote
Unread 02-28-2014, 02:19 PM   #9
mullis1
Registered User
 
Join Date: Aug 2012
Posts: 7
I have a 97 Jeep Wrangler Sahara ever so often oil pressure would drop to 0 on guage and check guage light would come on. After reading many threads on here and most everyone guessing I really found no real answer. I installed a new oil pressure sending unit while doing so installed a T fitting. Now I have a mechanical guage and the other line going out just like it was. After about a month the oil pressure guage dropped to zero but the mechanical guage was reading 38 psi. This tells me that its something from the oil sending unit to the guage thats causing it to drop to zero. Some threads have said maybe a bad connection at guages.
So for me this was good to see and this may not be everyones problem. If you are having this problem I highly advise to install a T-connecton at oil sending unit then connect a permanent mechanical guage also so that when this happen you will have a true reading.
mullis1 is offline   Reply With Quote
Unread 03-01-2014, 04:25 AM   #10
Renix
Registered User
1989 XJ Cherokee 
 
Join Date: Feb 2014
Location: las vegas, nevada
Posts: 132
Change oil pressure sending unit, change your oil fill plug there should be no oil on top of valve cover. You'll be surprised how much oil you can lose out of that little plug.check the back of the motor block and under the motor, oil pan and in between the tranny. The oil could be running off of the valve cover and burning off before you build up enough for it to drip. your belt if it squeals your losing drive on the alternator which could be causing your check engine and dash lights to come on.
Renix is offline   Reply With Quote
Unread 03-01-2014, 05:25 AM   #11
cruiser54
Web Wheeler
 
cruiser54's Avatar
1990 MJ Comanche 
 
Join Date: Oct 2009
Location: Prescott, Arizona
Posts: 9,811
Quote:
Originally Posted by CJRex0110 View Post
Had anyone had luck with this fix??

I have a similar issue and could use some help...

I have a 95 4.0 with fairly low miles. My jeep is more of a toy and not a daily driver. I noticed when it sits for a few days not more than a week that once it start it up the voltage and oil pressure are low. Sometimes when I drive a few miles both come back up and and all is good. Othe times it takes a few stops and restarts before it straightens out. If you drive at speeds above 50 the pressure gets lower and eventually the light comes on.

It almost seems backwards... When you sit at idle the pressure rises but when you take off the pressure drops the faster you go the lower the pressure gets on the guage. I replaced the gauge about 3 months ago and this issue just started a couple weeks ago.

Could it be the pressure sensor going bad? Would oil and voltage correlate to each other? Why does everything straighten out at the same time?

I notice that when the issue is occurring the the voltage drops lower and lower as you turn on the fan or headlights or anything that draws power...

The alternator is new and the oil has been changed fairly recent and still looks good. The jeep always seems to drive fine and has plenty of power even when the light comes on. Once you stop turn off the engine and restart the light is off and sometimes fixes the issue for a few miles or even a few days.?.?. Any ideas??
What brand of filter are you using?

Last time you serviced the battery cables at BOTH end?
__________________
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
Refresh*Connections*Before*Replacing*Components
cruiser54 is offline   Reply With Quote
Reply

Tags
gauge , oil , pressure
Thread Tools


Suggested Threads





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.