Hello, I have a 2018 Suburban. It started to make humming noise (or kinda resonance noise) a few months ago from under the carriage, I felt it was from somewhere under my seat or under the engine bay, however it could also be transferred from rear end.
When parking and neutral, it have never happened.
When speed below 40 mpg, it has never happened.
When coasting, it has never happened.
It only happens when I reach 45 mpg and beyond, the sound is come and go, when engine is cold, it happens more often and last longer each time. Well when the engine is warmed up, it is still there, but less often and last just a couple of seconds each time.
it looks like it only happens if I push the gas slightly and it will be gone if let off the gas. No noise at all when coasting, and no noise at all if I push gas hard to speed up. It has driven me nuts. Would appreciate any one who could provide some suggestions, a solution would be heartily appreciated.