Question for diesel gurus (strange failure 6.9idi)

diymirage said
How high did it rev before you killed it ?

(I know my diesel goes in high idle on its own from time to time...and I presume this is a new truck to you)

I didn’t rev it. It was idling and revved on it’s own.

it did a Christine

probably 300ish more rpm, didn’t redline or anything