Help! 1999 Jeep Cherokee Sport 4.0 Engine Rebuild Low 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 > Help! 1999 Jeep Cherokee Sport 4.0 Engine Rebuild Low Oil Pressure

FS: 2007-2013 Jeep Wrangler "HALO" Angel Eye KitFlowmaster's Force II Axle-back exhaust system for the 201FS: Wranger BRIGHT License Plate LED! Just $3! Great value

Reply
Unread 09-30-2013, 05:36 AM   #1
PilotPat24
Registered User
1995 YJ Wrangler 
 
Join Date: Apr 2011
Location: West Babylon, New York
Posts: 40
1

1

PilotPat24 is offline   Reply With Quote
Unread 09-30-2013, 06:30 AM   #2
CCKen
Web Wheeler
 
CCKen's Avatar
1999 XJ Cherokee 
 
Join Date: Jul 2011
Location: Canton, MI
Posts: 1,844
Did you replace the oil pump during rebuild?
__________________
If we have data, letís look at data. If all we have are opinions, letís go with mine.

Man who stands in front of Jeep gets tired. Man who stands behind Jeep gets exhausted.
CCKen is offline   Reply With Quote
Unread 09-30-2013, 06:40 AM   #3
PilotPat24
Registered User
1995 YJ Wrangler 
 
Join Date: Apr 2011
Location: West Babylon, New York
Posts: 40
.
PilotPat24 is offline   Reply With Quote
Unread 09-30-2013, 07:44 AM   #4
TheRealKTrain
Registered User
1998 XJ Cherokee 
 
Join Date: May 2009
Location: Houston, Texans
Posts: 1,685
So what were the results of the mechanical gauge you said you were going to run? I'm willing to bet your pressures are just fine. My 97 TJ used to do the same thing. The oil pressure sending unit and dash gauge are known to be terribly inaccurate.
__________________
"We are what we repeatedly do. Excellence, then, is not an act, but a habit." Aristotle

Μολὼν λαβέ
TheRealKTrain is offline   Reply With Quote
Unread 09-30-2013, 07:59 AM   #5
PilotPat24
Registered User
1995 YJ Wrangler 
 
Join Date: Apr 2011
Location: West Babylon, New York
Posts: 40
.
PilotPat24 is offline   Reply With Quote
Unread 09-30-2013, 08:27 AM   #6
CCKen
Web Wheeler
 
CCKen's Avatar
1999 XJ Cherokee 
 
Join Date: Jul 2011
Location: Canton, MI
Posts: 1,844
Quote:
Originally Posted by PilotPat24 View Post
I didn't check it with the mechanical guage yet. I'm going to do it this afternoon when I get home from work.

I just find it wierd that the guage read much higher prior to the rebuild...

Also, what makes the "check guages" light go on? is that from the sensor or from the actual guage on the dash? The check guage light went on when the guage on the dash dropped to zero...
The PCM puts the light on, based on voltage inputs from the oil pressure sensor.
__________________
If we have data, letís look at data. If all we have are opinions, letís go with mine.

Man who stands in front of Jeep gets tired. Man who stands behind Jeep gets exhausted.
CCKen is offline   Reply With Quote
Unread 09-30-2013, 08:37 AM   #7
PilotPat24
Registered User
1995 YJ Wrangler 
 
Join Date: Apr 2011
Location: West Babylon, New York
Posts: 40
,
PilotPat24 is offline   Reply With Quote
Unread 09-30-2013, 09:23 AM   #8
CCKen
Web Wheeler
 
CCKen's Avatar
1999 XJ Cherokee 
 
Join Date: Jul 2011
Location: Canton, MI
Posts: 1,844
Quote:
Originally Posted by PilotPat24 View Post
Could a bad ground cause an inaccurate reading

There is no seperate, external, ground for the Oil Pressure Sensor. But, if the connector pin sockets are corroded or damaged in any way it may have an affect on the sensor inputs to the PCM

or the fact that there are two wire harneess connectors not plugged into the a/c components since I removed them?
The AC electrical system won't affect the oil pressure sensor inputs to the PCM.
__________________
If we have data, letís look at data. If all we have are opinions, letís go with mine.

Man who stands in front of Jeep gets tired. Man who stands behind Jeep gets exhausted.
CCKen is offline   Reply With Quote
Unread 09-30-2013, 09:34 AM   #9
CCKen
Web Wheeler
 
CCKen's Avatar
1999 XJ Cherokee 
 
Join Date: Jul 2011
Location: Canton, MI
Posts: 1,844
Quote:
Originally Posted by PilotPat24 View Post
Yes, there was a new oil pump installed. It was an enginetech pump. Before putting the engine into the truck. I primed the oil pump and there was goof flow coming out of the oil filter hole. I then tightened up the oil filter to continue priming the oil and the drill wound up stopping when the pressure built up.

I sent the block out to a machine shop. Standard rod/main beraings and .020on the cylinders. They pressure checked the block and that came back fine.

Another thing worth mentioning is that the engine oil is very clean. It's not dirty at all.
The reason I asked about the oil pump was you said "when we were driving and we were making a left turn, the engine was idling and the psi went to around 15 directly to 0psi."

When you installed the oil pump was the pickup tube securly installed in the pump body? Did you install a gasket between the pump and the block, and torque the attach bolts down? Was the oil pump flush with the block at its mount point when it was securely installed?

You also said "continue priming the oil and the drill wound up stopping when the pressure built up." What drill motor did you use? I used a 120 volt/7.0 amp drill motor and it didn't stop. It slowed down some when the pump started pumping but it didn't 'stop'.

You did install a standard flow oil pump didn't you?
__________________
If we have data, letís look at data. If all we have are opinions, letís go with mine.

Man who stands in front of Jeep gets tired. Man who stands behind Jeep gets exhausted.
CCKen is offline   Reply With Quote
Unread 09-30-2013, 10:25 AM   #10
PilotPat24
Registered User
1995 YJ Wrangler 
 
Join Date: Apr 2011
Location: West Babylon, New York
Posts: 40
n
PilotPat24 is offline   Reply With Quote
Unread 09-30-2013, 04:45 PM   #11
PilotPat24
Registered User
1995 YJ Wrangler 
 
Join Date: Apr 2011
Location: West Babylon, New York
Posts: 40
j
PilotPat24 is offline   Reply With Quote
Unread 10-01-2013, 04:53 AM   #12
PilotPat24
Registered User
1995 YJ Wrangler 
 
Join Date: Apr 2011
Location: West Babylon, New York
Posts: 40
m
PilotPat24 is offline   Reply With Quote
Unread 10-01-2013, 05:27 AM   #13
PilotPat24
Registered User
1995 YJ Wrangler 
 
Join Date: Apr 2011
Location: West Babylon, New York
Posts: 40
j
PilotPat24 is offline   Reply With Quote
Unread 10-01-2013, 05:48 AM   #14
cruiser54
Web Wheeler
 
cruiser54's Avatar
1990 MJ Comanche 
 
Join Date: Oct 2009
Location: Prescott, Arizona
Posts: 9,775
Quote:
Originally Posted by PilotPat24 View Post
Also worth mentioning is that there is a Fram oil filter on the engine.
Ditch it and put a Wix on it.
__________________
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
Unread 10-01-2013, 08:12 AM   #15
PilotPat24
Registered User
1995 YJ Wrangler 
 
Join Date: Apr 2011
Location: West Babylon, New York
Posts: 40
m
PilotPat24 is offline   Reply With Quote




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.