CM2250 loud engine whine, need advice

[Rawze]

(11-01-2020 )suined Wrote:  Another thing I just thought of. The oil was brand new when I picked it up, the truck kept flashing regen needed on the way home, then the last 50 miles it actually derated. The oil already is black. I don't think this would cause a whine?

Send an oil sample to a reputable lab once it gets about 10k miles on it or so and not just have it done at an oil change place with one of those stupid quick-check machines. - See what is in that oil.