howling whinninng under hood
 

guys have 07.5 lmm dpf delete pcv reroute.got on light acceration what i call a howling whistle under hood .more dominant wen cold.and some boost ..im familar with turbo whinne.this is different.any ideas????

Are you sure it is not the engine fan? Those things can howl badly when starting up in the morning while cold.

no actually im not sure is not fan.i can tell when fan is engaged.thats just lots blowing
air.this is like a howl