CM2250 loud engine whine, need advice

[JimT]

(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?

Well that can't be good. Oil shouldn't get black that fast, especially only 100k mi after an inframe. While probably not directly related to the noise it most likely means your getting A LOT of soot pumped into that oil.

The air compressor being new catches my attention. Not sure if it would be the cause, but maybe someone didn't time it right when replacing the compressor?

Have you pulled the intake pipe off the turbo (leading to the CAC) to check for any oil leaks or inspect the turbine for wear or excessive dirt/soot buildup?

What about the cam/rockers/valves? have you pulled the rocker cover and inspected in there?

If all you have is a 400 mi trip home, presumably bobtail, then there's not much experience with this truck to lean on. Gonna have to do a lot of exploration and investigation. You mentioned being in PA. What part?