• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Oil pump musings...

Kejtar

PostMaster General
NAXJA Member
High flow or not? I picked up a used Mopar crate motor and the oil pressure is on the low side.... I've switched out the sensors and it's still on the low side, so it looks like its time to switch out the oil pump.

The question of the day is: high flow or standard? It seems that there are pros and cons to both..... btw, 97XJ with L6 ;)
 
first find out why it shows low pressure. scored or worn out bearings maybe? dont forget to check the cam bearings too.
 
Screw a mechanical gauge on it and find the real answer, 13 psi 10w-30 oil is normal standard ,hot, idle pressure.

YMMV
 
It's easier, faster and cheaper for me to swap out the oil pump :)


If the bearings are bad you are just masking the problem. Later down the road you will have a knock and have to take them out anyway. Just pop the oil pan and check them with plastigauge.
 
i have a melling high volume pump lying around and its new, i never got around to rebuild my engine so i just have it laying around and i will let it go if you want it
 
IMO, the only reason to use a high volume pump is if you intend to install an engine oil cooler. If a cooler is not going in, then the stock pump will be perfectly fine for the next quarter million miles or so...
 
The Mopar HV pump from Summit Racing works well. Now I have 50 to 55 PSi of oil pressure... My old rod bearings were just lightly worn, and a few were showing a little copper. Threw in +.001 King rod bearings when I installed the HV Mopar pump. Sure is cool to go from 9 PSi hot to 50 PSi hot !!! One more thing - I am using the WiX 51515R oil filter, and this thing has 214,000 miles on it. I have fixed 3 other Jeeps this way, and for the 4.0 engine, the Mopar HV pump from Summit Racing is just the best... http://static.summitracing.com/global/images/prod/norm/dcc-4529241_w_m.jpg Here is the link ---->>>> http://www.summitracing.com/parts/DCC-4529241/
 
FWIW Russ is not a fan of the high volume pumps Remi, I usually take his advice when it comes to engines :D
 
It's easier, faster and cheaper for me to swap out the oil pump :)
it's easier, faster and cheaper to put a bigger fuse in when one blows, too, but that isn't the right answer either :)

You need to find out what your real pressure is with a mechanical gauge and then find out what is causing it to be below spec.
 
ok, more background... I'm not out of spec on the oil pressure. It appears that at hot idle I'm at about 15psi (still need to confirm with a regular pressure gauge) ;)

I'm starting to lean towards not doing anything if the pressure at hot idle gets confirmed to be 15PSI plus ;)
 
I put a Melling HV pump in my 94 some 10 years ago. Did not have to massage anything, it all fit nicely.
 
After working at Dodge/Jeep dealers for many years and seeing first hand the engines apart and what fails and such. I don't like oil pressures under 22 psi at idle. It has been my experience that prolonged vertical climbing over 45 degrees causes oil pressureS to drop to zero and that it does not recover fast enough to keep the bearings from being scored with lower oil pressures unless you use an oil baffle in your pan. YMMV. :bunny:
 
After working at Dodge/Jeep dealers for many years and seeing first hand the engines apart and what fails and such. I don't like oil pressures under 22 psi at idle. It has been my experience that prolonged vertical climbing over 45 degrees causes oil pressure to drop to zero and that it does not recover fast enough to keep the bearings from being scored with lower oil pressures. YMMV. :bunny:

Update - adjusted belt tension, played with the wires on the sensor..... bought a manual gauge to double check findings...... got high pressure :) about 50+ psi at cold idle :) just under 40 psi at warm idle....
 
Cool then we wont have to do any of those rediculous repair on that infamous Rubicon trip!!!!:eek:
 
the law "stock gauges all lie" has been proven again!
 
yes, and it was before, which nearly got you to pull the pan off and replace the oil pump for absolutely no reason, because you trusted it.
 
JaVeLin,
How much clearance work did you have do to the pan to make the mopar pump pickup tube and screen fit?

The pan is easy to shape, and I worked it over on a sand bag with a ball-peen hammer for about 20 minutes, and just made it look rounder by the pump body. Still running great, and no leaks either. :yelclap:
 
Back
Top