Normal oil pressure?

[ScuderiaJEEP]

Curious what everybody's oil pressure is while running at idle or 2k rpm

Sponsored

 

[Hootbro]

Once warmed up, about 28-30 PSI. The Pentastar has a two stage oil pump and senses when to adjust up and down depending on RPM range and toque demand.

 

[PyrPatriot]

I usually get around 60-70 when accelerating. Coasting/mild gas in 8th gear stays at 31. Only noticed the increase after my first oil change. Wonder if the dealership added a little extra? Is that a thing?

 

[WXman]

Below 3,000 RPM it should run at around 30 PSI, and above 3,000 RPM the dual stage pump will increase pressure to around 60 PSI.

 

[kd1yt]

Does anyone know if the readout is really displaying as-measured pressure?

My last vehicle, a 2015 Ram 1500 Ecodiesel had absurd technology where a readout showed varying PSI, but all it really was was an "idiot light" type pressure/no pressure sensor augmented by a computer algorithm that displayed what the pressure would be calculated/expected to be based on temperature, RPM, etc....

 

[ShadowsPapa]

There are oil pressure sending units and oil pressure switches - the switch kicks in about 8 psi in prior vehicles to trigger the light. The sending unit is a variable resistance. If this is like any other vehicle, it should be real pressure, real-time.
The are right on the pressures. The issue is that people believe oil pressure is what protects the engine - it is not. You could run 10 psi as long as oil got to all the parts needing it. It's the film that protects - not the pressure.
Excessive pressure is a load on things, including the engine. It is one reason some people with older cars blow distributor gears (the distributor drives the oil pump in those engines) - they believe more OP is better, so the put in high pressure springs and pumps and they end up with more trouble, not less.
You only need as much pressure as is required to get oil to where it's needed - or in some cases like where they advance and retard the cam timing via oil pressure (Mercedes) the oil pump supplies the oil and pressure to advance the valve timing.

You can't possibly calculate the oil pressure because that will vary with viscosity and other things and some oils exhibit different viscosity at different temperatures than others.
I have oils on hand that will give very different pressures at xxx temp than others - can't be calculated. If your engine has bearings that are in spec but a tad large, toward the large side and the crankpins are in spec but on the small side, you have clearance in spec but a bit more than the clearance in my engine, then mine will run higher pressures than yours with the same oil because yours will leak more oil out along the way than mine.

 

[PyrPatriot]

There are oil pressure sending units and oil pressure switches - the switch kicks in about 8 psi in prior vehicles to trigger the light. The sending unit is a variable resistance. If this is like any other vehicle, it should be real pressure, real-time.
The are right on the pressures. The issue is that people believe oil pressure is what protects the engine - it is not. You could run 10 psi as long as oil got to all the parts needing it. It's the film that protects - not the pressure.
Excessive pressure is a load on things, including the engine. It is one reason some people with older cars blow distributor gears (the distributor drives the oil pump in those engines) - they believe more OP is better, so the put in high pressure springs and pumps and they end up with more trouble, not less.
You only need as much pressure as is required to get oil to where it's needed - or in some cases like where they advance and retard the cam timing via oil pressure (Mercedes) the oil pump supplies the oil and pressure to advance the valve timing.

You can't possibly calculate the oil pressure because that will vary with viscosity and other things and some oils exhibit different viscosity at different temperatures than others.
I have oils on hand that will give very different pressures at xxx temp than others - can't be calculated. If your engine has bearings that are in spec but a tad large, toward the large side and the crankpins are in spec but on the small side, you have clearance in spec but a bit more than the clearance in my engine, then mine will run higher pressures than yours with the same oil because yours will leak more oil out along the way than mine.

Every time you post something it reminds me of how woefully uneducated I am despite having several degrees. Progress is slow on learning about cars/mechanics - one hour each morning watching videos on how parts work. Do you have a book(s) you can recommend on learning about such matters for novices?

 

[kd1yt]

A number of technically competent people that knew the details of the Ram Ecodiesel really well all independently indicated that the Ecodiesel indeed did use the "proxy" RPM/ operating temperature calculation to arrive at a "displayed" varying oil pressure, there was even an aftermarket arrangement to be able to put in a different sensor to get valid readings with a reprogrammed ECU. Note that I am not saying that the calculation was valid, or that this is good engineering, in fact my point is that it was neither. My point is that just because you have a variable display that seems precisely calculated + indicated, may, unfortunately, not be reading accurate measurements. I hope that our rigs actually display oil pressure 'as measured' I'm just saying that after seeing what FCA did for an oil pressure "gauge" on the Ram Ecodiesels, I no longer assume that displays are grounded in reality.

 

[ShadowsPapa]

A number of technically competent people that knew the details of the Ram Ecodiesel really well all independently indicated that the Ecodiesel indeed did use the "proxy" RPM/ operating temperature calculation to arrive at a "displayed" varying oil pressure, there was even an aftermarket arrangement to be able to put in a different sensor to get valid readings with a reprogrammed ECU. Note that I am not saying that the calculation was valid, or that this is good engineering, in fact my point is that it was neither. My point is that just because you have a variable display that seems precisely calculated + indicated, may, unfortunately, not be reading accurate measurements. I hope that our rigs actually display oil pressure 'as measured' I'm just saying that after seeing what FCA did for an oil pressure "gauge" on the Ram Ecodiesels, I no longer assume that displays are grounded in reality.

I would hope to heck it's real - that estimation stuff is not just BS, but actually more difficult that actually measuring and feeding the info into the system to display on any chosen place.
But if you didn't like that system, there was notice late 2016 that an oil pressure sensor kit can be ordered as an add-on. ->

>>This add-on includes the tune modifications and hardware necessary to replace the factory "dumb" oil pressure switch with an actual oil pressure sensor; this will also replace the data displayed in the instrument cluster with the real measured oil pressure instead of the modeled values used with the switch.<<

Not sure of the source of the kit.

 

[Hootbro]

My 2018 RAM 2500 with the 6.7 Cummins reported a algorithmic leveling/smoothing oil pressure reading for the cluster and not a true one. My understanding is because the oil pressure could vary so much wildly, it was to cut down customer service visit and concerns about oil pressure. Basically so long as the true PSI was above 6 pounds, the cluster would just lie to you for oil pressure.

 

[ShadowsPapa]

My 2018 RAM 2500 with the 6.7 Cummins reported a algorithmic leveling/smoothing oil pressure reading for the cluster and not a true one. My understanding is because the oil pressure could vary so much wildly, it was to cut down customer service visit and concerns about oil pressure. Basically so long as the true PSI was above 6 pounds, the cluster would just lie to you for oil pressure.

Too many people worry about what it SHOULD be - and the typical cut-off for the OP switch used with "idiot lights" was 8 psi. The TSMs would say to check pressure and if it was 10 or above it was ok.
People freak if they see a lower number because it's been drilled into them - wrongfully so - that high is good, more is better, so if they have a friend bragging about 60-80 psi they freak if they are under 40.
So I guess I could see why they might do that, a placebo in a sense. See, it's fine, don't sweat it.

 

[ShadowsPapa]

Every time you post something it reminds me of how woefully uneducated I am despite having several degrees. Progress is slow on learning about cars/mechanics - one hour each morning watching videos on how parts work. Do you have a book(s) you can recommend on learning about such matters for novices?

My HS auto shop teacher told me one time a few years after I graduated that I'd lived more lives than most people twice my age.
I'm super-hyper, can't shut it off. I absorb like a sponge.
I started at 14. Spent all my waking hours in my shop. I completed HS requirements in 3.5 years, took an additional class and worked afternoons as a mechanic in my final year of HS. My parents fully supported me (not with money, they had little, but moral support, encouragement. And if I wanted a mini-bike or go-kart, since they couldn't go buy it - I had to make it myself.
To make money to pay for college, I worked as a mechanic 4pm to 10pm pretty much daily, and full days on weekends.
Right out of college I worked in a shop where our normal work week was 52 hours.

I'm just wired very different. My thinking processes are very different so it's hard to explain.
I can't shut out the stimuli. A normal day is extremely exhausting and stressful.

Books - I have my college books, most of them were pretty good - dated as far as systems now - little talk of injection, modern ignition and such but I found that if you learn the basics, the specifics can be figured out. They are actually still good because the basics, the logic, the science behind it all hasn't changed.
I'm careful about youtube because although there's some great info out there, very good - there's also a lot of mis-information put up by people who once changed their own oil, the car still runs ok, so now they have their own youtube channel and are the neighborhood car guru.
Thankfully if they allow comments, the bad ones get some interesting comments down below. LOL

 

[Beowulf85]

I usually get around 60-70 when accelerating. Coasting/mild gas in 8th gear stays at 31. Only noticed the increase after my first oil change. Wonder if the dealership added a little extra? Is that a thing?

Check your oil level my dealership put in 6 qt I had to empty 1 out when I got home.

Sponsored