PLEASE help me! VNL670 with an ISX CM2350 4.4 MPG!

[VNL670]

(06-26-2018 )snailexpress Wrote:  I will look blowby first. If truck was idling a lot it's about time to have cylinder polishing and carbon seized rings. Why oil pan gasket was changed?
How about overhead? How frequently regeneration is occurs?

Actually I don't think there is a lot of idle time on this engine because it had idle shut down after 2 minutes of idling, so I had the idle shutdown removed when I updated the software on the ECM because it was driving me crazy. There is no blowby on this engine at all (knock on wood!). The oil pan gasket was changed because it had an oil leak but later discovered the leak is actually coming from the valve cover towards the rear. I won't be able to confirm it's coming from the valve cover until I take it in to the shop and do the overhead valve adjustment on it. It is very hard for me to tell in regards to the REGEN, but they occur while I am driving (passive) or I do it while I am parked manually when it let's me. But I go thru I fill-up of DEF for every 4 to 5 fuel fill-ups.