Insight on a Cummins N14
 

Not being familiar with the bigger Cummins' anymore, are the N14's any good? Inherent problems? Things to watch out for? General reputation? Looking at a truck with 750k on the odometer and wondering how close to the end of its' life this N14 might be if it's been well taken care of.

The N-14 is bullet proof. They are 1 million plus mile motors.

Thanks Guardrail, that's what I was looking for.

What about the 'M' series motors? Same thing?

I'm looking to get a new truck and I seem to keep looking at trucks with either the M's or N's.

L-10

M-11

N-14

K-19

L10/M11 are different than the N14 and the K19 is different than all of them. but the 11 was a replacment for the 10. The number is the displacement of the engine is Liters. can't really compare a 10-12L engine to a 14-16L engine though. the M/ISM are pretty reliable, theres TONS of urban busses running the M series and I've seen lately quite a lot of firetrucks/pumpers with a 500hp ISM. and allison.

Arguably, ( because we all have our own opinions ) The N14 was quite likely the best engine cummins ever put together for a highway application. Lots of power, pulled great down low, didn't hog down fuel, and if you didn't overspeed it, would run with minimal problems for a LONG time.

The newer engines are nice, but they don't go nearly as long before they start having problems.

I completely agree.

We have 4 of them, an occasional injector or crank sensor, thats it.

Scott, check the idle oil pressure with the engine at full operating temp. It should be right around 20psi then 40 above 1000 rpm. If it is lower the 15 psi at idle then it most likely needs cam bearings, (big job). A standard bearing roll "will not" improve oil pressure. However, if the low oil pressure buzzer does not sound when taking off loaded then I would not be overly concerned.

Thank you everyone! This is exactly what I was looking for. I need to know everything I can because I'm not familiar with these bigger engines and more than likely whatever I look at will be quite a ways from home.

Tim, those oil pressure readings are what I'm getting with my 466 now, so they'll be easy to remember!

T-Rad has agreed to go look at a truck for me that's down his way, (sorta!). I'll make sure he sees this.

Tim
The only other grief I have experienced with the N14, besides timing sensors and push tubes from overspeed, is the wiring behind the engine, leading to the battery box.

Yeah, that special wire that provides all the power to everything electronic... and is the only place that green doesn't mean GO.

But yeah, bulletproof.

We rebuilt the N-14 I'm driving pulling 105,500 lbs at 875K miles only because I had a water leak in #6 cylinder. It's always been dependable & I have 985K on it now. I'll turn a million miles at my next oil change. The last truck I had was a 400 big cam 3 cummins & we traded it off for a new one at 1,400,000 miles with one in frame at around 900K

How well does the rest of the truck stand up with that many miles on it? Sloppy rears? Loose tranny's? All kinds of rattles in the cab, etc. I realize a lot depends on how well it was cared for in the first place, but in general how do things fair?

I've driven a freightliner cabover with 2.4 million kilometers on it that was in 100x better shape than most of the 1.0M km< fleet conventionals that I have to work on.

IMO it is impossible to speculate.

I don't know much about the N14 other then that I have heard they are bullet proof, but wit that said I work for truck reconditioner as my job well I'm in college, and you can have an 07 come in that is just trashed cause no one took care of it, and you can have 2000's come in that are tight as the day they drove off the lot cause they were well cared for.

i love this engine, like stated before main thing with them that seems to go the most is injectors, and engine position sensors, the cam boxes like to leak every now and then, and some may already know this, but the gasket thickness on the cam boxes actually determines the timing of the engine, it's weird, and kinda a pain to have to adjust. as long as the truck you are looking at has been somewhat cared for, and maintenence has been kept up, that engine should keep on runnin, i love the way the sound idling, maybe even more so than my B engine....

Wes

Well the truck I was looking at was sold Friday afternoon. [verymad] But as I continue in my search, I'm going to try to find something with the 'N' engine in it. Seems like it's what I'm looking for in terms of reliability, longevity and power.

Thanks everyone!