Oil Pressure Concern

[JExpedition07]

When I replaced the timing chains, camphasers, oil pump, tensioners and guides in my 5.4 3V I filled the gerator housing with fresh oil and put the backer plate back on the pump. Before starting the engine to protect the new chain guides from a slapping chain you needed to pressurize the chain tensioners. These are tensioned by oil pressure. It took a solid minute of foot to the floor (doesn’t allow truck to start) cranking before the oil pump finally primed. I thought I was going to need to pull it back apart. The OE pump provides around 25 psi at a hot idle, the replacement for around 30 psi. That truck is still running at 240k in my buddies hands.

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[Samson16]

I'm surmising the oil pump is not crankshaft driven?

 

[JExpedition07]

I'm surmising the oil pump is not crankshaft driven?

I believe the 3.5 is crank driven, but it still utilizes a solenoid to lower pressures at low load. The 5.0 and 2.7 are crank driven off a COG belt, and utilize a similar variable volume solenoid.

 

[Samson16]

I believe the 3.5 is crank driven, but it still utilizes a solenoid to lower pressures at low load. The 5.0 and 2.7 are crank driven off a COG belt, and utilize a similar variable volume solenoid.

I’m trying understand. I’m familiar with solenoids acting as pistons or plungers, so is it pushing open a valve to adjust the volume? The oil pump impeller speed is a function of crankshaft RPM correct? I guess I haven’t thought much past thick viscosity/higher psi and vice versa.

 

[JExpedition07]

I’m trying understand. I’m familiar with solenoids acting as pistons or plungers, so is it pushing open a valve to adjust the volume? The oil pump impeller speed is a function of crankshaft RPM correct? I guess I haven’t thought much past thick viscosity/higher psi and vice versa.

This explains it, Ford is utilizing an electronically actuated plunger

 

[Samson16]

This explains it, Ford is utilizing an electronically actuated plunger

The only statement missing before the unit levitated into the box was “Reduced engine life expectancy” lol

 

[Samson16]

Thanks for helping me. It’s a transmission for your oil pump!

 

[Snakebitten]

3.5 Ecoboost

 

[md2000]

Gents, pulling up an old thread here but having same low oil pressure concern as the OP first wrote about. My 24’ STX 5.0 is displaying a “normal” idle pressure reading just at or slightly below the first line marker on the left side (more less 1/3 reading on the digital gauge). But with throttle and torque output it’ll jump as high as the midpoint.
Is it consensus that this is normal with the new bypass oil pumps? Or is this indicative of an issue? (First 5.0 F150, recall my 07’ 5.4 being stable). Also, right around 300 miles so far, so early break-in…..appreciate the feedback.

 

[jasonkosi]

Gents, pulling up an old thread here but having same low oil pressure concern as the OP first wrote about. My 24’ STX 5.0 is displaying a “normal” idle pressure reading just at or slightly below the first line marker on the left side (more less 1/3 reading on the digital gauge). But with throttle and torque output it’ll jump as high as the midpoint.
Is it consensus that this is normal with the new bypass oil pumps? Or is this indicative of an issue? (First 5.0 F150, recall my 07’ 5.4 being stable). Also, right around 300 miles so far, so early break-in…..appreciate the feedback.

My 24 5.0 is the same. I’m thinking Ford changed the readout on the digital dashes for 24 and now it shows more accurately, rather than a yes/no value. At normal hot idle in mine (500rpm) it sits at about the first mark on the gauge. You can even see it move when you put the truck into park as the rpms go up slightly, so does the oil pressure.
Just finished changing the oil on mine for the first time and put the full 7.75 quarts (7.5 litres) in and the gauge still sits at the first mark at idle.

 

[Gros Ventre]

I installed an oil pressure gauge. What I see is around 45-50# or at higher power 95-100#. These vary a bit with oil temperature. The oil pump is a vane type positive displacement pump. It has a variable volute controlled by a solenoid. The default or de-energized position is the high pressure setting in case the electric circuits fail. The pressure readout is driven by a switch that is set somewhere around 5-8#. The dashboard readout is a computer programmers idea of what you want to see. Bottom line: either the switch is closed or it's open, that's all. I'm rather unhappy that the switch is set so low, if you're pulling a heavy load on a hot day going up a grade, I believe by the time the dashboard shows a problem damage has occurred.

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