Why your 6.4L is making oil and how to stop it from killing the bearings.

[StateLineStance]

I checked my dipstick today and it was an inch above the full mark. It smells like straight diesel. I know the 6.4L uses the 8th injector stroke for regens, but this seems excessive. Is my DPF clogged, or are my injectors leaking internally?

 

[DirtRoadDiary]

What you're seeing is fuel dilution, and it’s the number one engine killer for the 6.4L. When the regen cycle is interrupted, the unburnt diesel washes past the rings and thins out your oil. How you fix this is by shortening your oil change intervals to 3k miles or, if your local laws allow, deleting the DPF to stop the post-injection cycle entirely.

 

[ColdSteelCrank]

What happens on these 6.4Ls is that short trips kill them. If the engine doesn't get up to operating temperature long enough to finish a regen, that extra diesel has nowhere to go but the oil pan. how you stop it? Most guys eventually solve this permanently by deleting the DPF, which stops the post-injection cycle entirely. If you can't delete it, you need to change your oil every 3,000 miles religiously to keep the dilution levels manageable.