This noise sounds like the engine is dieseling or something, but I really dont know if it is the engine or the transmission. It happens when the truck needs to kick down a gear but hangs a bit when I press the gas. At first I thought I had some bad gas so I went and put a full tank of 93 octane in it. The noise is still there. It gets worse the longer the tranmission dosnt kick down a gear, but when it kicks down and the RPMS kick up it goes away. Any help would be great thanks.