Thanks Willerus,I did not know
that the 365 was without a wastegate,it uses this variable vane setup.I would assume however it has to dump like a wastegate thus making the sound.Thats why I thought it was like my other navistar engines they all did it and i never had any issues with them with lots of miles.I dont seem to have a problem with the noise even my f350 does it and it has since new.