Gen 3 oil pressure

[Robottrainer]

Noticed some interesting things with oil pressure on a 200km 2021 PP1 Mustang GT auto. With the Roush kit, the oil recommendation bumps to 5W50. Warm and at a 600rpm idle, oil pressure reads 18 psi. At 2000 rpm it sits around 45 psi. Once the rpms and load hit a certain level the pressure shoots up to 95 psi. Makes me think the pressure is regulated by the PCM.

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[ice445]

It's all mechanical. The faster the oil pump turns via the crankshaft as RPM's increase, the more oil is pumped through the engine and the more restriction there is, which raises the pressure to the needed levels for all the components before it can drain back down into the pan. That's why worn motors have low oil pressure, all the bearing surfaces and such are worn out and let too much oil past so you never get that proper build up and film strength. And why a thicker oil results in a higher oil pressure reading. Fluid dynamics are fascinating and this is a caveman explanation, I'm sure someone else can improve on that.

The one interaction that could be computer related that I'm not sure of is how all the cam phasing system works, I know it's hydraulically pumped up to perform its function and activated by a solenoid, but I'm not sure if it causes a drop in oil pressure when it's operating, or if it's a fixed loss and stays filled the duration of operating over all conditions.

 

[W.O.T. Stang]

My stock 2019 does the same thing. It concerned me at first until i realized that every single one does the same thing. Enjoy!

 

[Coosawjack]

The oil pressure in my 2019 car seems to be regulated by the computer since at low RPM's and high load the pressure shoots up.....2000 RPM's can see 90+ PSI with 0W30 Mobil I.........while hot idle pressure is about 18 PSI!!

While driving it's all over the place but at 60 MPH in 6th gear on flat roads it runs about 25 PSI...it jumps up dramatically with throttle increases but minor RPM increase......so it seems to me the PCM does the oil pressure controlling??

 

[bauern]

The oil pressure on 2018+ coyotes is regulated by the pcm. If you look at the oil filter housing you'll see a solenoid that will bleed oil back to the pan.

 

[boB]

The oil pressure on 2018+ coyotes is regulated by the pcm. If you look at the oil filter housing you'll see a solenoid that will bleed oil back to the pan.

Yep, there is an Oil Pressure Control solenoid connected to the PCM (per the 2019 service manual wiring diagrams).

 

[Coosawjack]

Well then....there you have it....another Mustang Mystery SOLVED!!

 

[Robottrainer]

Yep, there is an Oil Pressure Control solenoid connected to the PCM (per the 2019 service manual wiring diagrams).

My instincts are usually pretty good. I suspected as much or I suspected the signal from the PCM to the gauge is slow and not real time. Typically any mechanical pressure relief system will see the pressure pretty linear (as RPM increases so does the pressure at pretty much the same rate). This is more "controller" where it stays around the same psi for a range of RPM but does a huge change as the rpm/load increases

 

[W.O.T. Stang]

The oil pressure on 2018+ coyotes is regulated by the pcm. If you look at the oil filter housing you'll see a solenoid that will bleed oil back to the pan.

Great info! I didn't know that. Thanks for sharing.

 

[ice445]

The oil pressure on 2018+ coyotes is regulated by the pcm. If you look at the oil filter housing you'll see a solenoid that will bleed oil back to the pan.

Very interesting, definitely didn't know that. I wonder what logic it uses to open/close that valve.

 

[Coosawjack]

It seems it uses engine LOAD as well as engine RPM's from what I can tell from the digital gauge in the cluster!!

 

[ice445]

It seems it uses engine LOAD as well as engine RPM's from what I can tell from the digital gauge in the cluster!!

Yes, but why is my question. More oil pressure isn't always a good thing, so there has to be some logic it's following. Maybe to keep more oil entering the valvetrain under load?

 

[Coosawjack]

Probably has to do with fuel economy......less OP load increases fuel economy and PCM to only increase OP to protect engine when loads and RPM demand it??

 

[W.O.T. Stang]

My guess it to aid in the variable valve timing at higher rpm's. That's a lot of friction over 32 valves at almost 8000 rpm.

 

[opengl]

Pretty sure I remember reading that it was done mainly for fuel economy reasons.

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