low oil pressure

[sdryde]

.060 bore
10.25 cr
.054 head gasket
zero decked
24lb injectors
stock renix fuel pessure reg
comp cam
comp lifters
mopar spings and retainers
7120 head polished and gasket matched
99+ intake
STOCK renix tb
renix computer

33" tire
4.88:1 gears spooled


I did not replace the oil pump durring rebuild and after the motor fully warmed up ie oil temp up the oil pressure slowly crep to 0 psi and the lifters were clacking the next step was replacing oil pump..after replacing the oil pump,..I now have pressure of 13-16 psi at full temp @idle in gear..and now only one lifter is complaining...While i replace the pump I did pull all the rod caps and observed good bearings wear.....


help me please....this is my first rebuid---justin

 

[wolfpackjeeper]

What oil are you running? Did you prime the pump before starting?

 

[sdryde]

started with
maxima break in oil (high zinc)
changed the oil to:
valvoline racing 50 wt High zinc)
changed the pump
pump helped a little bit but not the answer to the problem

at cold start up oil pressure 65psi then once the motor warms up it creeps down to 12-15 at idle give a little throttle and it goes back to 30-40psi

 

[Talyn]

What is your bearing clearance like?

 

[wolfpackjeeper]

at cold start up oil pressure 65psi then once the motor warms up it creeps down to 12-15 at idle give a little throttle and it goes back to 30-40psi

This is within specs is it not?

 

[Talyn]

Minimum at idle is 13psi. At 1600rpm and above 37-75psi. For a new engine his numbers are low. Are you reading the pressure using the stock gauge or a mechanical gauge?

 

[sdryde]

the oil gauge is aftermarket electric....I am looking through my old stuff to find my mechanical gauge to verify the reading, but so far can't find it

 

[CherBear]

0331 head?

 

[Talyn]

7120 head polished and gasket matched

0331 head?

Good job there Watson

 

[CherBear]

Good job there Watson

I have a knack for missing the obvious. :banghead:

 

[sdryde]

I drove it to Wholesale Automotive Machine aka WAM in San Diego (by the way great shop and excellent customer service, A 5 star shop imo) I had one of the engine builders listen to it and he told me to:

#1) verify oil pressure with meachanical gauge

#2) bring him the pump with out seperating the pickup so he could check it out

he seems to think that maybe it is sucking a bit of air between the pick up tube and the pump. hopefully tomorrow I will have time to do this.

 

[activeshooter1]

during ur rebuild did you replace the cam bearings? if not well........
if so is it possible that you didn't get the oil jurnals lined up?

screw it put lucas in it and run the poooo out of it

 

[wolfpackjeeper]

screw it put lucas in it and run the poooo out of it

Because lucas will fix anything right? I am a firm believer in lucas but this is just a retarded statement. The idea is to fix the problem, not to just cover it up.

 

[Talyn]

screw it put lucas in it and run the poooo out of it

That is awesome advice for a newly rebuilt engine.

 

[JJacobs]

Hell yeah, throw a little Slick 50 in there too and screw the oil! Oil pressure is for sallies. Do they still make Slick 50?

Did you put the plug in the oil galley underneath the front cover? I've forgotten that before.. once. It's the kind of thing you don't do twice.

 

[eflores]

that much loss in oil pressure when warm and running VR1 50wt scream main bearings to me...Jacobs is spot on also. leaving an oil galley plug out will do it every time....but i think you would see far less oil pressure with a half inch hole in your oil galleys

 

[live24wheel]

Hell yeah, throw a little Slick 50 in there too and screw the oil! Oil pressure is for sallies. Do they still make Slick 50?

Did you put the plug in the oil galley underneath the front cover? I've forgotten that before.. once. It's the kind of thing you don't do twice.

X2 I just read about a guy over on JeepStrokers that forgot that plug. Seemed to be about the same issues. Threaded oil galley plug behind the timing cover.....

 

[JTwthaXJ]

Hey! hey! hey! You have what sounds like the same issue I am having! Please trouble shoot first dont pour in these magic elixirs and think its as permanent fix. I had my 4.7L in for about 4 months and 1500 miles before I had to snatch it out again for a new timing chain. Had the same engine shop go through it replace bearing etc. Got it back in and I have the same problem still. NO TO LOW OIL PRESSURE (5-30 tops.) I replaced the oil pump with a Hesco Blueprinted pump and still no worky. Moral of the story is get more than one opinion before taking a major investment to an engine builder. I am going to check bearing clearances and look to see if the oil galley plug is there. Reputable engine builder in Raleigh that builds strokers for fun and another one here in FV said run 15-40, no zinc additive need. They both do it for race engines and in their daily drivers. My two cents...

 

[sdryde]

live24wheel,

I just looked for that thread could'nt find it could hook me up with a link?

 

[Talyn]

There isn't much to it. Guy had low oil pressure and it turns out he forgot to put in the oil galley plug that is under the cam cover at the top, under the cam gear.