Gray green substance under oil cap - Cummins ISX15

[Nilao]

Sounds to me like maybe its wrist pin slap or possibly it broke a piston? Either way your going to be pulling the head to get to the bottom of this. Alot of blowby would indicate a broke wring or a hole in a piston.

Would a malfunction in the injector cause this issue without throwing a code? Doubtful but I rule nothing out until verified.