Cummins Oil Pressure

[UpDown]

For 25 years of driving three Ford F53's with their V10's, I switched to a Newmar Northern Star with a Cummins B6.7 360 HP. I'm a bit concerned about engine oil pressure. The Freightliner chassis has two different oil pressure gages - one a bar graph, and one a standard dial gage. The dial gage has a narrow red line from 0 PSI to about 40 PSI (no clear scale). Newmar provides two manuals, one a Newmar and one a Freightliner, but no Cummins manual. The only oil pressure discussion in both manuals is a statement that minimum oil pressure should not be less than 7 psi at idle. During normal operation (60F OAT, 1700 rpm, 195F engine temp, and relatively flat road) the oil pressure runs between 45 and 47 psi. As this is so close to the "red line" on the dial gage it tends to make me a bit unsettled (currently have only about 6K miles). Is this a normal operating pressure for the engine? (BTW at idle it does have about 19 psi in the same OAT and engine temp)

[jacwjames]

Create an account on the https://quickserve.cummins.com/info/index.html
Once you have an account register your engine using the SN


From there you will have access to all the manuals and repair information. Takes a little bit of effort to learn how to maneuver through the website but well worth it.


I gave up on my dash gauges long ago and installed a Silverleaf VMSpc and set up the screen for the info I want to track. I do track oil pressure and even have an alarm for low pressure set up. On my 8.3 I'll run ~55 psi at hwy speeds and +20 at idle unless it is extremely hot.


You might look at a Bluefire system to monitor your engine and other critical stuff. Same principle as Silverleaf but it is Bluetooth and you can use your phone to monitor.

[Skip426]

There are several threads in the Cummins engines forums about obtaining engine info direct from Cummins linked to your engine serial number .

Maybe even a pdf of the engine owners manual /

JMHO ; The Cummins ECM is monitoring all the engine functions , should oil pressure fall into a critical area you'd very soon be seeing engine derate and shut down warnings.

Have you info on the brand of oil and filter currently in the engine ?

Regular oil or synthetic ? Cummins oil filter ( Fleetguard ) or another brand ?

EDIT: I see Jim posted while I was typing ... boy I type slowly.

[d23haynes57]

I would be more concerned if oil pressure was low. What is the oil pressure right after engine start? That would indicate the pressure setting of the oil relief or control valve. 45 psi would be a common setting. I think things are perfect as they should be for a new engine.

[UpDown]

first, thanks for the links to Cummins information

regarding oil/filter - the coach is brand new, so it is the original oil/filter installed by either Cummins or Freightliner

regarding start up oil pressure, it depends on weather temperature or whether I am using block heater...but typically is in the 60+psi range

[Dutch Star Don]

Your oil pressure is fine. My ISL runs similar to jacwjames at about 55psi. Your Cummins computer is pretty smart and will surely let you know if there is an oil pressure issue.

You can't get too wound around the axle about what you think these gauges should be reading. The manufacturer's gauges are just not that accurate. I also run the Silverleaf engine program and see exactly what the Cummins ECM sees.

As you drive, you'll see what are the norms and know what your engine is doing. It's when they very from what you always see that you need to be concerned. Otherwise, you'll make yourself crazy worrying about something that isn't there.

[UpDown]

All, thank you…I have ordered a Cummins owners manual (may order other documents), will rely on Cummins system monitoring, continue to monitor what’s normal, and try not to fuss. BTW this unit has the Freightliner “glass dash”…which is amazingly accurate for fuel consumed (for example when it says 55 gallons consumed, I can count on it being with a gallon of that) so I have some confidence in the gages

[VentanaOdyssey]

I have the B6.7 360 in my Ventana and my oil pressure does the same thing. I was like you a bit nervous so I called Cummins and they told me perfectly normal.

[Dutch Star Don]

Originally Posted by UpDown

All, thank you…I have ordered a Cummins owners manual (may order other documents), will rely on Cummins system monitoring, continue to monitor what’s normal, and try not to fuss. BTW this unit has the Freightliner “glass dash”…which is amazingly accurate for fuel consumed (for example when it says 55 gallons consumed, I can count on it being with a gallon of that) so I have some confidence in the gages

You can install the Bluefire system that connects to your Jport near your left foot. Then mount a cheap tablet or small laptop to the left of your steering wheel. Bluefire lets you see all the things the ECM sees ACCURATELY.

On my system, I have oil pressure, water temp, turbo boost, trans temp, speed, Allison gear your in, rolling HP, Rolling Torque and lastly, intake manifold temp. Cummins doesn't look at exhaust temp, but intake manifold temp for overheating issues.

Here is a photo of mine pulling one of the steepest grades in So. California. It shows I hit 450 HP and 32.8 turbo boost. I was getting 1.7 mpg.

[Skip426]

[QUOTE=
Here is a photo of mine pulling one of the steepest grades in So. California. It shows I hit 450 HP and 32.8 turbo boost. I was getting 1.7 mpg.[/QUOTE]

All those ponies , need to be fed I consider " instant fuel economy, scary ; to say the least .

[Dutch Star Don]

Originally Posted by Skip426

All those ponies , need to be fed I consider " instant fuel economy, scary ; to say the least .

Yeah, but I get 99mpg going down the hill. However, it never seems to balance out.

[UpDown]

As follow up, I received the Cummins manual - it states, low idle minimum 10 psi and at rated speed minimum of 30 psi

[Rbailess]

Electric gages are never precise. Back in time all trucks had direct oil pressure gages a little oil line from the engine to the gage. In present day it’s a sending unit thru the ECM. The old direct gages were way more accurate.

[Dav L]

Originally Posted by Rbailess

Electric gages are never precise. Back in time all trucks had direct oil pressure gages a little oil line from the engine to the gage. In present day it’s a sending unit thru the ECM. The old direct gages were way more accurate.

Not at all accurate.
All depends on the particular gauge.

The electric gauges provide the potential to provide DTC (diagnostic trouble codes) which can tell the ECU to alert the driver, slow down, stop engine. The old mechanical gauge never had those smarts. The DTC goes into memory. So, when a mechanic is trying to diagnose, he/she can see "what happened and when".

The pressure read out is really not all that important to the driver. More important for the system that is actively monitoring that many times a second. In reality, it could go gaugeless as watching stuff on the dashboard all the time keeps eyes off of road. Oil pressure 99.99% of the time is just fine. No reason to watch. You only need to know when the .01% kicks in and then, what to do.

When I see the "digital laptop dashboard" with a zillion readouts displayed for the driver, I just see the numbers of front end crashes increasing....these aren't opinions, these are facts (I was one of the persons in automotive that was responsible for such systems).