I had the same issue, except on the passenger side. It was indeed the safety belt assembly, it was buzzing like mad from the day I purchased the car and driving me crazy. It could be easily reproduced simply by tapping anywhere in the vicinity of the belt.Hi,
I took my Ascent to the dealer yesterday to look into a vibration noise behind my head on the drivers side. After looking into it all day, they feel it is the driver seatbelt assembly. They don't have one (and are ordering a replacement), but say it is ok to pick up because it isn't a safety issue. You all know a lot more about cars than I do. Do you agree that it isn't a safety issue? It sounds like it can't be fixed until next week at the earliest.
I appreciate the feedback.
Instead of going to the dealer, I decided to investigate it myself. I removed the plastic facade which was easy. I then unbolted the seat belt assembly. As soon as I did that, the seatbelt retracted into the mechanism and would not release. I had to look up on Google how to release it which consisted of specific pull and release sequence that is not obvious. However, in doing so, it somehow resolved the vibration issue. I reassembled everything and the problem has thankfully not come back. I don't recommend that anyone else try this though because of the retraction issue and the fact that the safety belt mechanism contains a small explosive charge. Bring it to the dealer.
I have several other vibrations, rattles, and squeaks that I'm still tracking down. One in the driver's side door, and several others in the rear which I've not yet found. Many cars squeak and rattle, but the Ascent seems particularly susceptible. A pity because it's otherwise a nice quiet ride.