This spring I bought an new 08 that had sat all winter, so I changed the oil in the first few hundred km's. After the oil change the dipstick showed 1/2 inch above full, which it maintained till the next change. I changed the oil out at 6,500km and sent off a sample to Blackstone Labs. It came back with <.05% fuel in the oil. Of the 6,500km 2,500 were towing a 12,000 lb 5th wheel. The rest was mainly 25-30 km trips, with some short 2-3km trips. After the last oil change the dipstick still shows 1/2 above full. The dealership I use adds the book quantity of oil.

So it seems fairly consistent for the 6.7L to show 1/2 inch high on the stick. The question I have, is it really overfilled, or is the indication off?

 

These emmision systems are not normal either. Making oil is not normal of course. All the injectors overfuel as this is how the emissions system does its job. Evidently the emissions system and EPA could give darn about rapid catastrophic failure. This is not a "special case" as there are a lot of overfull motors and dipsticks of the 6.7L out there.

Similar to the older days when a too rich gas motor condition would wash the oil from the cylinder wall and rapid catastrophic wear and failure would occur.

So, what would you do with your immediate attention given there are no mechanical issues found?

My emmisions fell off and up for inspection as my attention was grabbed and I am in no hurry to get it back on since it does not work properly. Yes, it may pass a test designed by the EPA, but it does other things that are not correct as well.

 

The best way to find an over fueling cylinder that can not be electronically diagnosed is to remove the exhaust manifold and fire it up. You will have either excessive smoke or more probably flames coming from the suspect cylinder.

Let me give you an example. One of my N-14s had flames coming out the stacks when the driver returned from a call. Truck had a small intermittent skip at idle but ran fine going down the road. Infrared gun aimed at each cyl showed exhaust temps were mostly uniform, Insight showed all was well. Pulled exhaust manifold fired it up and found #3 acting like a flame thrower. I just put 6 remanned injectors in this truck that were rebuilt by Metro Fuel Injection, same company as Midwest Fuel Injection. Well out it came and in with a Cummins reman injector.

 

Oil quantity can also increase from soot loading.

What soot %age are people seeing on UOA?

 

Funny thing is that you've described a basic principle of operation for the 6.7L emmisions system. Not 1 flame throwing injector, just multiple events from them all to produce the temps in the exaust needed to do its job.

Hence, there is no issue really other than principle of operation and the "side" effects. These side effects are considered "normal" and although they do get ones immediate attention there is still nothing mechanical to be found. It would suck to do all that work and find nothing as I'm sure has been done many times on these motors.

What you say may be a leaking injector is that they are all designed to "leak" just enough to cause the high after treatment events as well as get lost into the oil. Along with all that soot from the EGR!

 

I am aware of the 3 injection events. 1- precombustion, 2- main combustion, 3- post combustion to keep the cat hot and excited for the gas transfer. As far as I know all dpf equipped trucks use fuel supplied to the burn chamber to "regen" the dpf. This process does not happen through the injection events.

 

Just to toss in a couple more cents. Some time ago I posted about my 08 6.7l surging under light throttle conditions from take off. Contacted a friend who is one of the best 6.7l techs in Texas. His immediate repsonse was "over full crankcase" because of the making oil issue. The over full condition does not allow proper draining of the turbo oiling system and causes the turbo to hesitate. His normal course of action on oil changes is to go back with 11.5 qts at a change to allow for the "expansion". That is what I did and the problem is gone and I have a new procedure and oil change interval.

The problem is worse with trucks that don't get worked hard and frankly mine hasn't gotten a ton of hard work since I got it in May.

 

Actually, I think there is a 4th one and that is for the DPF. Your 5.9L has 3 events.

Fuel supplied to the burn chamber? This sounds like a jet turbine engine. How is this fuel supplied to the burn chamber? Low pressure fuel, high pressure fuel, injector?

Anyway, it is shot through the exhaust (4th event) where the fuel originates from an injector and pumped through the motor into the exhaust where needed. It is the 4th event that creates the temperatures needed, not fuel supplied to a burn chamber. The system has a CAT, then NOX filter, then DPF which gets cleaned like a BBQ with fuel originating from the 6 injectors.

Hence, this process is what allows fuel (and soot) into the oil and per the original post.

That is interesting about the high oil levels affecting the drain of the turbo and causing issues. Makes sense.

 

I guess the fuel line and ignitor on the "burn" chamber/dpf are there for show? Not sure how Dodge does it, however, I would love to see how a 4th injection event supplies enough superheated gases to turn soot to ash without melting a piston?

 

On the Dodge application there is no fuel line to the DPF, thats only on the bigger rigs.

Dodge does inject fuel thru a 4th (and I have heard 5th too) injection event to superheat the exhaust. It doesn't melt pistons because the event is so far into the power/exhaust stroke there is maximum heat rejection.

 

Good info, thank you.