Low oil pressure after warmed up. Missing Galley Plug. Galley Plug locations

[BearitvRanger]

1989 ford ranger, 2.9v6 manual STX

I could really use some help locating where this Galley plug is supposed to go
View attachment 56450
there is 3 in total, two are already installed on the back of the block just next to the freeze plug.
(if you look to the front of the block, left, you see a galley plug is placed in the oil pressure sensor hole next to the engine mount, this is not correct)
View attachment 56452

I NEED to find where this Galley plug is actually goes. any help would be fantastic. the block is now installed so I cant easily look the block over to find it.

 

[Transman304]

If you are having low oil pressure after warm I dought it's going to be a galley plug. Need to look more at oil pump or bearing clearances.

 

[RonD]

+1 ^^^

Yes, if you were missing an oil galley plug you would have no oil pressure to speak of cold or warm, and probably a mess on the floor under the engine

Whats the actual pressure reading warm, above 8psi at 700rpm idle is expected
Ford changed to an Oil Pressure switch because of this, people would often come in to dealers to complain of lower oil pressure when they used "real"gauges, lol
So they put in a 5psi switch so gauge showed "good pressure" after start up as long as pressure was above 6psi
Under 4psi you will start get valve train noise, gravity being what it is you need a bit of pressure to push the oil up higher in the engine

Oil pressure is the oil that the engine CAN NOT USE at that time, its the pressure of the oil thats backing up in the main oil passage, so pump is sending out more oil than the bearings and lifters can pass at that RPM
As RPMs go up pressure goes up because pump sends even more oil volume than bearings and lifters can pass, the bearing gaps don't change, lol, but do pass a bit more oil as they spin faster

 

[Transman304]

the bearing gaps don't change, lol, but do pass a bit more oil as they spin faster

Hi @RonD,
I’m not sure I understand the what you posted on “bearing gaps don’t change” what bearings were you referring too?
Thanks
Brad

 

[dvdswan]

Did you or have someone rebuild the engine recently? Galley plugs are normally on the front and back of the engine. If it were a rear galley plug missing you'd have oil all over the ground after spitting on the flywheel. Front however, oil would stay in the engine.

That being said, as @Transman304 and @RonD mentioned, oil pressure would constantly be low not just after warming up.

Going back to the rebuild question. When rebuilding the engine where bearing measured for their clearances? As @RonD stated "bearing gaps don't change". If you had a bearing gap on one of the bearings; main, rod, camshaft, doesn't matter, if one or more of those had a larger than normal clearance it could create your symptom.

If you believe that an oil galley plug is left out. Don't run the engine until you find where it is missing.

 

[RonD]

Hi @RonD,
I’m not sure I understand the what you posted on “bearing gaps don’t change” what bearings were you referring too?
Thanks
Brad

Oil pressure goes up as RPMs go up because Oil pump increases its output, but the places the oil can get out, like the main, rod and cam bearing gaps doesn't change, the flow increases slightly at increased RPM, but the unused oil backs up much faster in the main passage so pressure goes up
So 8psi at idle(800rpms) could be 40psi at 4,000rpm as pressure backs up
General rule of thumb is 10psi per 1,000rpm

Main, rod and cam Bearings do wear down(larger gaps) over 100's of thousands of miles, so this would show up as overall lower oil pressure than when an engine was new