Priming engine only 38 psi oil pressure

87we410877

Well-Known Member
I just got my engine in and all. I am priming the oil pump with a drill, 600 rpm's and I am reading 38 lbs on the oil pressure gauge. Is this normal? I thought it was supposed to be around 60 psi.

Also, when I let off the drill I immediately hear a gurgle sound like slurping soup for about a second coming from in the engine. wtf is that?
 

robzombie

Well-Known Member
That pressure is normal. A running engine is at 750/800 rpm.

The noise you hear, is it coming from the pan area??

If so that could indicate a loose pick up or missing gasket.
 
Seems like that sound would be caused by air in the oiling system, pushing out from some clearances in the engine. I hear that often when priming engines, as the oil fills the system and pushes out the air. But, it stops after a few minutes of priming. If the pump is constantly drawing in air and entraining it in the oil; you may have a problem with the suction screen gasket to the block (as robzombie said) or possibly the timing gear housing gasket I would want to be sure about this before setting the engine in the car.

Another possibility is the oil pressure regulator valve. It moves in its bore to regulate the pressure, then after you stop turning the pump, the regulator spool moves back to the at-rest position. As it moves, it could possible draw air and cause a sound.
 

TTipe

Snake Skinner
I have a TA front cover & I'll try priming with a 0.5 " electric drill. I suspect that this drill motor may be marginal?
 

Jerryl

Tall Unvaccinated Chinese Guy
Doesn't sound normal to me.
600 rpm (take 550 loaded) is 1100 engine rpm. A cold engine oil pressure is typically 70-80 psi. Seen 50 before nd it didn't turn out good. I would be searching.
 

87we410877

Well-Known Member
So basically this doesn't look good. Awesome. This is a brand new long block from ATK engines and I personally installed the pickup so I know that the gasket and tube are installed correctly. The last engine I primed significantly slowed the drill down and put a load on it. This time, barely noticing a difference in the load put on the drill.

Can I get the pan off while in the car? The motor is installed and everything hooked up from the ac and MAF to plug wires. Ready to run
 

87we410877

Well-Known Member
That pressure is normal. A running engine is at 750/800 rpm.

The noise you hear, is it coming from the pan area??

If so that could indicate a loose pick up or missing gasket.

I can't tell. I hear it through the oil fill and basically everywhere. I'll take a vid this week
 

ek02

Well-Known Member
I usually get 60 PSI at that drill speed with 10-40 or 10-30 oil. I always use TA adjustable oil pressure regulators to set the pressure at 60 while priming and end up with 20 at hot idle and 70 at 6000 RPM. Try using a heavier relief spring or shim the existing spring with a short 1/4x20 allen head bolt to see if the pressure comes up. Not sure what could be making the noise. I don't recall hearing any noise when letting off the drill. Keep priming until oil comes out of every rocker. Keep the covers on if you have stud mount roller rockers. Shaft mounts don't usually shoot oil everywhere like stud mounts do.
 

ek02

Well-Known Member
QUOTE="87we410877, post: 3720864, member: 16548"]So basically this doesn't look good. Awesome. This is a brand new long block from ATK engines and I personally installed the pickup so I know that the gasket and tube are installed correctly. The last engine I primed significantly slowed the drill down and put a load on it. This time, barely noticing a difference in the load put on the drill.

Can I get the pan off while in the car? The motor is installed and everything hooked up from the ac and MAF to plug wires. Ready to run[/QUOTE]

If this is an ATK rebuilt, 38 PSI may be normal on a stocker. I've seen stock rebuilt V6's that only have 35 PSI revved up and 10 PSI at hot idle.Try boosting the relief spring tension.
 
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87we410877

Well-Known Member
QUOTE="87we410877, post: 3720864, member: 16548"]So basically this doesn't look good. Awesome. This is a brand new long block from ATK engines and I personally installed the pickup so I know that the gasket and tube are installed correctly. The last engine I primed significantly slowed the drill down and put a load on it. This time, barely noticing a difference in the load put on the drill.

Can I get the pan off while in the car? The motor is installed and everything hooked up from the ac and MAF to plug wires. Ready to run

If this is an ATK rebuilt, 38 PSI may be normal on a stocker. I've seen stock rebuilt V6's that only have 35 PSI revved up and 10 PSI at hot idle.Try boosting the relief spring tension.[/QUOTE]

Thank you. I will try that. Not really sure what you mean by the 1/4 20 bolt. Is that installed already and I just turn it in?
 

TTipe

Snake Skinner
Doesn't sound normal to me.
600 rpm (take 550 loaded) is 1100 engine rpm. A cold engine oil pressure is typically 70-80 psi. Seen 50 before nd it didn't turn out good. I would be searching.
I'm asking if a. 5 " drill motor (don't) know the wattage / amps will prime my new engine. 746 watts=1 hp.
 

TurboBuRick

Moderator
Staff member
I always prime oil pumps with the motor on the stand. Much easier to fix if there is a problem.

Sounds to me like the oil is being relieved inside the motor. There are a couple things that come to mind.
Wrong lifters (un shrouded roller) could expose the oil ports in the lifter bores.
Other thing that comes to mind is the plugs are missing for the oil galleys on the front of the engine.

The good news is that you caught it before the engine was run and any damage can be done.

Rick
 

robzombie

Well-Known Member
It's a ryobi and it's got a 600 / min marking on it so I'm assuming that's 600 rpms

That rating would be with no load. The drag from the oil pump would slow it down considerably reducing RPM.

If you find out what/where the sucking noise is and correct it you will be fine.

Don't shim the spring or use any other method to raise oil pressure until you verify pressure with motor running.

To high a pressure is just as bad as to low.
 

Steve V

Steve V's Automotive 757 560 2782
Atk, reman?? probably has bearing clearences way too loose, wrong pistons, wrong crank ete, etc---beware of what you are getting into.
 

ek02

Well-Known Member
Is the front cover and oil pump off your old engine, and did it have good oil pressure? Did the new engine have dowel pins on the front of the block to locate the cover? On the intake side is the gasket mating properly on the pick up and front cover, and is the screen off the pan 1/4"? If all that is good, then it has to be too much bearing clearance or a plug leaking or missing in the front of the block. I would call ATK's warranty department for guidance if everything is good that you can check without going into the long block.
 

TURBOELKY

Well-Known Member
I've burnt deWalt electrical drills priming an engines, and twisted the top right off a priming tool. There should be a significant change in sound of that drill motor, AND smoke coming from it once primed:D

The other members are right on the money with what they are saying. It was asked but is the front cover GM or TA or China? The China covers taper down to about 3/8" where it feeds the oil galley. If it's China, take it off and modify or replace. That holds true for even the vendors front covers here unless it's from TA.
 
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