N14 Celect+ (Producing coolant...?)

Hi all! Motor is the n14 celect plus with 1.25 million miles. December it started puking coolant from the over flow. I never noticed a fuel smell, but my dad said he was smelling something other than coolant. I never thought it was fuel solely due to getting 7.8-8.8 mpg in the winter (much better than prior years). Talked with our mechanic Friday (02-07) and he said injector cups. Called in and Kevin said the same thing. At this point, 2 months later, I assumed it was fuel and our mechanic gave me the assurance it was. On the phone with Kevin I lost service so he never heard my question fully.

So here it goes:
At 1.25 million miles, do you continue to tear down the motor and do a rebuild or should we just do enough to fix the problem that is current? I will be buying this truck next year off my dad as he will be getting a glider. On this current motor we can see 8-9k miles before adding a gallon of oil. It runs extremely well for a 1.25 MM motor. Right now I am factoring money aside for IF a rebuild is needed AFTER I purchase it. The question we are finding difficult is doing just what is needed to stop the fuel leak, or go to town on a thorough rebuild? (Pittsburgh power crank damper, all seals/gaskets replaced, micro blue bearings, etc...) .

The input will be highly appreciated! This becomes a gamble because if the motor dies in 3 months after fixing the current issue, we can't say we didn't see it coming. My problem is why do the extra motor work when it is running the best it ever has. Then again it could die tomorrow (a bit extreme but you get the idea).

Thank you for taking the time to read this. If anymore info is needed I will get to it!

 

Appreciate the responses! Oil samples have been top notch and the coolant samples came back excellent. Which makes me wonder if they test for fuel in the coolant sample. I'll check out Napa and see if I see any test kits. Thanks!

 

HAHAHA! Harley you made my day with that. I'll be honest, I very rarely agree with Kevin. I'm still learning on the trucking end, and will keep learning. However the physics end I disagree with much of what he claims. That's just me though. The oil samples come from a lab, so all good there. In June I am going to check the clearances, providing they don't get done sooner. I've got the shop manuals so that sure helps. The best thing I like from PP is the power box. The best about Kevin... the entertainment!

Now with the cups, wouldn't the heads need any attention to? Or am I looking too far into the shop manual? If I can get it into the shop Thursday I'll be content. I'd love to do it myself, but I lack the confidence.

Off topic... I hate the DPF motors. I strongly hope I'll never have to own one, but that's wishful thinking.

 

Excellent info john! I can't get it into my shop till next week, though looking back I've had this issue for a while. I have a 1 gal jug hooked to the overflow and it has filled up in exactly 1 week. Approx 2800 miles and 1 day of idle time. Noticeable amount of diesel. Got a few quotes from 17-22k for full out of frame rebuild plus 2 weeks down time. Ideally I just get heads and injector sleeves and new injectors (have reman ones w/ 300k on them but I plan on putting new in during rebuild so will do them now).
Funny that in November I replaced the oil cooler since oil was getting in the coolant due to o-rings being MIA. Now the oil sent its buddies in the fuel department for a visit. Needless to say I'm skeptical on doing a rebuild, yet would be livid if days after this prob is fixed the motor goes. Doubtful, but could happen.