Is it just me or is it just weird that everyone that has an 04-05 Cummins is having this ring problem? There is a few on this forum and I have found several on other forums, including a couple Cummins that were at the shop for the same thing while my truck was there. It seems like all of a sudden it's like BAM everyone has a ring problem

 

I would say there's lots of reasons, Injectors washing the walls. Maybe the new oil?

 

It could be the combination of the new oil and LS fuel.

The only thing that doesnt make since is the #6 is normally the one that goes out first.

 

Well, with poor filtration, Water in the fuel, Poor pulse or scavenge capability's from the exhaust manifold , and no coolant bypass around the back of the head it's easy to see that 5 and 6 are hotter, making the effects of cylinder wash or injector failure more evident and more likely to cause catastrophic failure.

 

the new oil is supposed to be better "less ash" which also means less abrasive that is actually suspended in the oil; same with the diesel fuel... sulfur is supposed to be an abrasive. removing it is a good thing but the process of removing the sulfur toasts the lubricity of diesel. manufacturers are supposed to add enhancers; but with any kind of fuel stored in a tank... quality diminishes with storage so you never really know what you're getting. which is mainly why guys run a small bottle of 2 stroke oil to every tank of their fuel; gains have been debated but i think peace of mind is more valuable than any "gains". just on a hunch cylinder wash down sounds like the cluprit; if there was any kind of added contamination it'd either be spread evenly or the majority of it introduced to the cylinders with the shortest distance to the air supply and such. then again this is just my reasoning

 

I guess my thoughts are directly related to how does excess cylinder temps effect an injector. I think most factory injectors will be leaking around 100K if not before.
Also Zinc dithiophosphate may have somthing to do with it as well. We all know its at a much lower because "zinc and phosphorus both damage catalytic converters and DPF Systems."

 

The Bosch distributor said that 125k is about it for CR injectors, with 150k pushing it. After losing my engine at 109k, from now on, more filtration,and new injectors at 100k.

I just wish there were some way of KNOWING an injector is leaking, since in my case the engine ran perfectly, no fuel was going into the oil, and other than gouges in 2 places, there was no wear in the cylinders. I do plan to check the exhaust runners with a non-contact pyrometer looking for colder cylinders to see if that tells me anything.

I run 200:1 fuel/2cycle oil mix.

STP and some other additives used to be LOADED with Zinc dithiophosphate ant-wear additive-maybe it still is and is warranted for extra protection, though I understand diesel oils HAVE more anti-wear additives since they still use non-roller lifters.

Bob