Oil Sending Unit

[Neophyte]

As a brand new owner of the M817, I've noticed the oil pressure at 60PSI at Idle and 90 at about 1500 RPM on the Cummings NHC-250.

The oil guage reads 0-120. Is it possible the wrong sending unit was installed (0-60) vs. the 0-120....? Is there another problem that would cause the idle psi (after warmed up for 30 mins) to run at 60psi and 90 at speed?

Thank you

Bob

p.s. The picture is with the engine just started....showing close to 90psi at idle......??

 

[WillWagner]

CUMMINS...not cummings.
90 psi is normal at cold start. You are correct thinking that the sender and gauge aren't matched. Should read around 30 at hot idle and 50-60 at 2000 or so RPM hot.

 

[dozer1]

Here is a generic answer to oil pressure gauge concerns that I cut and pasted from the last time I posted it.

When I have oil pressure gauge concerns, I like to get a new mechanical one (which are pretty inexpensive) and hook it up to wherever they read the oil pressure on the engine. That means remove the electric sending unit if the truck has an electric gauge, and hook up the hose for the new gauge there. You can then see what is really going on for oil pressure. If everything is OK, you can then go on to change the stock sending unit or gauge. If your truck HAS a mechanical gauge to begin with and it reads incorrectly, the gauge is no good.

It's been such a long time since I started my M817 that I dont remember what the heck they read. I believe it is a mechanical gauge. (correct me if I am wrong anyone please) so if it is, and reading high, the gauge is the culprit. To me it doesn't sound like you have any real problem to worry about.

 

[AMGeneral]

I am about 100% sure all 800 series trucks came factory with mechanical oil pressure gauges,so unless your gauge itself is the culprit,most likely that is the correct oil pressure.

It has been a while,but I think that is about where my 816 kept the pressure at while operating.

 

[Neophyte]

Thank you Gents. I'll leave it alone. Cummins.....got it (I worked in Peoria in my late teens......CAT I know how to pronounce......Cummins, getting familiar with).

 

[dozer1]

Peoria , hmm sounds like you might need an A3 for that inevitable 2nd MV purchase.

 

[WillWagner]

Ahhh...Clatterpillar!!

 

[Neophyte]

Haha.....my wife thinks I'm going through a mid life......but c'mon.....what guy doesn't point and go "****, that is cool!". I'm so new to this, I can't even think about adding more, but from past experience ....all of our hobbies look better in pairs:

1967 Chevy II Wagon- 580 Dart Big Block, Tub'd wheels, 700+ at the wheels
1991 Mustang Gt - Completely refurbished to stock (with a "little" extra under the hood to remind the younger rice burning generation of what American muscle is all about)

753 Bobcat
JD 3720

And an embarrassing of $$$ in R/C Aircraft (i.e. why I went to "insurable" hobbies....watching thousands turn into a pile of kindling got old.....and they all crash)


Is there a "Hi. I'm Bob" type addictive FMVA (FormerMilitaryVehicleAnonymous) group in this hobby too?

Having fun!!

 

[dburt]

Neo, I had a '91 'Stang GT convertible once. Wish I still had it. Back in the day a friend supercharged his '90 'Stang GT and it ate rice burners for breakfast. But some of these new rice burners are impressive and might smoke the old 'Stangs.
Don't worry about saying 'Cummings' instead of Cummins. I drove Ford Powerstrokes (some say 'Powerhoax') many years, and then thought I would try a Cummins. My Ford friends said the Cummins didn't know if it was 'cumming or going' and the Chev folks don't talk to me anyway, so I had to learn to say Cummins instead of 'Cummings' too!
So far I like the Cummins, but don't care as much for the Dodge cab as well as I felt about the Ford's cabs.
So- when I get my 813 5-ton someday I may feel right at home with the Cummins and the uncomfortable cab!