Suddenly 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 CJ Forum > Suddenly low oil pressure

FS: Wrangler RGB Multicolor Fog Light LEDs: Awesome EffectSavvy Aluminum Gas Tank SkidFS: 2007-2013 Jeep Wrangler "HALO" Angel Eye Kit

Reply
Unread 02-18-2013, 02:18 PM   #1
stripperguy
Registered User
2005 LJ Wrangler 
 
Join Date: Mar 2010
Location: Schenectady, NY
Posts: 277
Suddenly low oil pressure

Here's the story--
Only about 20k miles on my 10 year old full 258 rebuild.
Always had great oil pressure, hot or cold, idle or 2,000 rpm.

Then I noticed that my hot idling oil pressure would drop to nearly zero, and the engine would run rough too. If I rev it up some, the oil pressure is mostly back to normal, and the engine smooths out too!

Background:
Comp cam 252 I think, with matching hyd lifters
high volume oil pump
calibrated mechanical oil pressure gage
Weber 38/38
Clifford intake, Hedman hedders
New (20k ago) main bearings, rod bearings, cam bearings, new 20 over pistons and rings.

My S-I_L mechanic is thinking I could have collapsed lifters...what do you guys think??

__________________
1977 CJ5 still building
2002 TJ---gone but not forgotten
2005 LJ insurance wreck, finally got the bugs out
stripperguy is offline   Reply With Quote
Unread 02-18-2013, 09:39 PM   #2
Double8racer
Registered User
1984 CJ7 
 
Join Date: Oct 2012
Location: Cleveland, Ohio
Posts: 32
although mechanical gauges are rather reliable have you tried another gauge and inspected the existing line for any possible leaks.
Double8racer is offline   Reply With Quote
Unread 02-18-2013, 09:59 PM   #3
Jeepkid1995
Registered User
1979 CJ7 
 
Join Date: Nov 2011
Location: kelowna, British Columbia
Posts: 201
Maybe a stupid question, but did you do in oil change in there somewhere and use a different oil weight? I used to have nothing at idle hot or cold, but then I changed the oil to a 15/40 diesel oil, and I get strong oil pressure all through the rpm range. And x2 on a leak in the oil line to gauge
__________________
->'79 CJ7 (VIN Says it's a 5, wheelbase says otherwise), 6 inches of spring lift, awaiting an MC2100 on a teamrushed MSD'd 258

-->350 time. '95 block SBC, stroked to 383, dremeled heads and big 'ol intake, maybe a Holley 750 CFM, not sure yet

--->"Safety? Buy a Volvo. Never buy a CJ, or a Chrysler Jeep knock off, for safety, fuel mileage, reliability, handling, ride, comfort, aerodynamics, quietness, convience, stability, low maintenance cost, performance, or ease of use. The only reason to buy a CJ is because you are absolutely, incurably nuts." -OldTexas
Jeepkid1995 is offline   Reply With Quote
Unread 02-18-2013, 11:23 PM   #4
BagusJeep
Web Wheeler
 
BagusJeep's Avatar
1981 CJ7 
 
Join Date: Jul 2009
Location: Bali, Indonesia
Posts: 4,381
You could have leaky lifters, but it is probably your oil. When was the last time you changed it and what did you put in?
__________________
BagusJeep lives in Bali, the Land of Temples.
With a Jeep every prayer counts.

1981 CJ7 258ci - Bagusjeep
1984 CJ7 258ci - Puthijeep
1981 J20 258ci - Gladys
1995 Cherokee 4.0 - CHEROKEE
BagusJeep is offline   Reply With Quote
Unread 02-18-2013, 11:45 PM   #5
86cj74.2L
Web Wheeler
 
86cj74.2L's Avatar
2004 WJ 
 
Join Date: Jul 2006
Location: Stouchsburg, PA
Posts: 6,480
Gassed oil comes to mind.
86cj74.2L is offline   Reply With Quote
Unread 02-19-2013, 12:45 AM   #6
WSS
Ps:91
 
WSS's Avatar
1972 CJ5 
 
Join Date: Oct 2012
Location: Chino, Ca
Posts: 2,193
A double gasket on the filter maybe? I notice in equipment that a wix filter will run lower pressure than a fram often due to more filter volume (less back pressure). Some brands also have a bypass if it gets too clogged.

The running rough suggests somthing like this. If you can get a oil sample done, it will tell you the health of the motor too just to rule out the gassed oil from bad rings or some gremlin in the motor ($$)

WSS
__________________
www.metaltechus.com

Our Yellow 72 CJ5 build thread

Yellow Jeep club member #73802
WSS is offline   Reply With Quote
Unread 02-19-2013, 05:15 AM   #7
stripperguy
Registered User
2005 LJ Wrangler 
 
Join Date: Mar 2010
Location: Schenectady, NY
Posts: 277
Thanks, guys.
My first thought was gassed oil...I did an oil and filter change (straight 30 wt) with no benefit.
And I verified my oil pressure gage accuracy and inspected for leaks. I also substituted another mechanical oil pressure gage, the low idle pressure is definitely for real.

What puzzles me is the sudden onset of these symptoms, I had 10 years of flawless performance, and then BAM!!
__________________
1977 CJ5 still building
2002 TJ---gone but not forgotten
2005 LJ insurance wreck, finally got the bugs out
stripperguy is offline   Reply With Quote
Unread 02-19-2013, 07:26 AM   #8
Truck633
GO ONE MORE!!
 
Truck633's Avatar
 
Join Date: Jan 2007
Location: Las Cruces, NM
Posts: 1,481
I didn't have a sudden drop like that, however the oil pressure at idle was 1-3 psi. With higher revs it would come up, but only to about 18-22 psi max. I installed the Snelling high volume pump, and the low idle pressure didn't move, the top end would come up about 8 psi higher, but it wasn't the fix I was looking for. My next step (wich may be yours as well) is to check and probably replace main bearings.
__________________
____________________________________________
You don't need a parachute to skydive... You need a parachute to skydive TWICE!!!

Up here - we go by results, when you preached, people slept. When he flew, people prayed.

Quote:
Originally Posted by vindicated View Post
It's like dads new mistress. You hate her until you see her boobs.
Quote:
Originally Posted by ionakana View Post
I bet the new bike riding monkey will pedal a lot faster!
Truck633 is offline   Reply With Quote
Unread 02-19-2013, 07:56 AM   #9
Matt1981CJ7
Web Wheeler
 
Matt1981CJ7's Avatar
1981 CJ7 
 
Join Date: May 2011
Location: Elbert, CO
Posts: 10,034
I think the SIL may be right. Or you have an obstruction, somewhere.

Oil pumps will also fail. Once, I even had a new pump that wouldn't hold air, right out of the box.

Matt
Matt1981CJ7 is offline   Reply With Quote
Unread 02-19-2013, 10:08 AM   #10
stripperguy
Registered User
2005 LJ Wrangler 
 
Join Date: Mar 2010
Location: Schenectady, NY
Posts: 277
Quote:
Originally Posted by Matt1981CJ7 View Post
I think the SIL may be right. Or you have an obstruction, somewhere.

Oil pumps will also fail. Once, I even had a new pump that wouldn't hold air, right out of the box.

Matt
I'm still in the middle of a SOA mod...once that's done, I'll dig into the oil pressure mess.
I'm considering a higher performance camshaft, would swap in new lifters at the same time.

Oil pump? You know, I did install a high volume pump back when, but I reused my old pick up tube. That tube is only held in by interference fit...what if it somehow shook loose??!!

I guess I should drop the pan and check out the mains and oil pump...
__________________
1977 CJ5 still building
2002 TJ---gone but not forgotten
2005 LJ insurance wreck, finally got the bugs out
stripperguy 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.