Cummins N14 making a noise

I just purchased this truck so figuring out all the thing last owner neglected

When you get up around 2000-2200 rpm is makes a winning noise like the blower motor is going out but it sounds like its coming from under the hood the blower motor is off, it drivers fine no loss of power and once you get off the pedal it goes away. It kinda sounds like its in the dash but I dont know of anything in the dash that could be making that noise its kinda loud, there is no vibrations.

Any ideas let me know

 

It does it with a trailer under a load at lower RPMs too. Only time it goes away is at low rpms or going down a hill or off the power. The motor has 100,000 on it from a Over Haul the air compressor needs changed because its pushing oil in the tanks thats getting fixed but sounds like in the dash I did change rpm gauge but not sure that could have anything to do with this.

 

peterbilt 379 dual breathers
I checked all the connections, we did change a pass threw coolant tube on 5-6 so all the intake was off but I checked it and seemed fine Ill have to go take a another look