Samford

About twice a day I get a sudden loud humming while accelerating. It's only when I'm slowly accelerating at about 1500 rpms. I can only hear it inside the cab. If I accelerate faster it goes away. Any insight would be appreciated it.

60DRB

My 4.6 has a spot in the rpm range where it has a louder harmonic hum on accelleration. I just add or reduce throttle and leave that range.