Hello fellow drivers my name is Joe and i'm new on here. I have a question for those that are familiar with cummins N14. I bought a truck that has a Cummins N14 celect 460 in it and it uses alot of oil, 4 gallons between oil changes (12k Mi)... I had a detroit 12.7 with 2.3 million miles on it and oil leaks everywhere, that engine used 2.5 gallons of oil between oil changes. This N14 has 727k miles and uses 4 gallons and no leaks anywhere! To me engine sounds good when idling but it's weak on pulls, my brother has the same truck but with small M11 cummins 400hp, and he outpulls me on hills or flat ground. What do you cummins guy's have to say about this? Also truck stalls when i try sliding tandems on my trailer, when i start it back up it throws a real dark cloud of smoke. Thanks in advance.
Sounds like she's ready for an inframe. leak points are front accessory drive bushing, and cam followers. If it's dry for leaks, then that is some horrendous consumption of oil for that motor, even at those miles. What weight oil are you running?
Thaks for the reply! I'm using 15w40 mobil delvac with lucas. Also my fuel milage won't go past 4.8mpg no matter how i drive.
More than likely, a hole in a piston. I had a NHC400 (predecessor to the N14) that had a hole in number 6 piston. Ran fine, other that loss of power, and oil consumption. For what it’s worth, a M14 (or any 855cid) is the cheapest truck engine to do a rebuild on. No tricks to rebuilding either, except you’ll need a in/lb torque wrench to set the injectors. I’ve rebuilt several myself.
IMO, the torque wrench adjustment method is the most accurate way to set the injectors, and is also what is specified in the Cummins manual.
The adjustment is actually made by adjusting the screw. A torque wrench can be used to bottom out the injector to clear it of fuel, but that's it's only purpose. Basically to prevent a heavy handed tech from not causing damage trying to over bottom the injector.
