New motor with no low oil pressure at idle

Well, I just did a big motor build on my truck and I am having issues. Low/No oil pressure on the low side at idle and Low psi while driving. (I am talking about LPO not HPO)

Truck runs and drives, just takes a long time to start (I am assuming its because it takes that long to get oil to the HPOP)

Checked with a snap on pressure gauge through the oil cooler housing sensor
Idle - 0 PSI
1000 rpms - 7psi
2000 rpms - 15-20 psi
3000 rpms - 20-25 psi

Will not go above 25psi


I have checked all the easy normal stuff...
HPOP check ball valve is good
Complete new front cover with oil pump
Replaced oil galley plugs (2 front, 3 in back)
All 8 piston squirters were installed with loctite


I opened up the oil filter housing and checked the filter drain back valve and its seems to be good, I swapped it with a known good one just in case. While cranking over the motor it fills up the oil filter housing really quick... no issues supplying volume, just no PSI.



Anybody have any ideas before I pull open this brand new motor and start tearing into it :doh:


Motor build includes:
All new main/rod bearing STD size
Polished crank (not reground)
RCD billet stage 2 cam with new STD bearings
.040 mahle pistons
upgraded lifters
billet push rods
oring heads
etc...
etc...

Pick up tube o ring? Which check valve did you check in the housin? Ive seen issues with the removeable plastic one on the base and heard of problems with the one thats under the cover that bolts under the oil filter.

Checked the relief valve for debris?

HOOV3R said:

Checked the relief valve for debris?

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This. That would explain good volume but low psi.

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6.0 Tech said:

Pick up tube o ring? Which check valve did you check in the housin? Ive seen issues with the removeable plastic one on the base and heard of problems with the one thats under the cover that bolts under the oil filter.

Click to expand...

I personally put the pick up tube oring on myself... but that is going to be checked next if/when we pull the motor

I have checked both check valves... I replaced the one in the front cover when I put on a brand new front cover. I checked the one in the oil filter housing, and swapped it with a known good one.

HOOV3R said:

Checked the relief valve for debris?

Click to expand...

I have visually inspected both... I will double check.

KCTurbos said:

I have visually inspected both... I will double check.

Click to expand...

It should just fall out with no spring pressure.

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Hey charlie before you take it back apart, let me look at it for you. I know we talked a little on the phone about this, I would like to look at it for curiosity sake.

Dieselmore said:

Hey charlie before you take it back apart, let me look at it for you. I know we talked a little on the phone about this, I would like to look at it for curiosity sake.

Click to expand...

Thanks. I will give you a call later today

I've seen the check valve in the bottom of the filter housing fall out causing no oil pressure at idle but as soon as you throttle it will show pressure. Just an idea.