Located Source of Buzzing Noise Under Vehicle

[Rook126]

As with many of us, this buzzing vibration noise has been eluding me for months. It sounds like a heat shield or thin metallic sound just as some of you have described. I typically only hear it randomly at very low speeds and rpm such as when I am turning into a parking space or reversing slowly. I'm certain it still happens at higher speeds but I don't really notice it because of wind/road noise or the music being turned up. 

 

I've seen the other posts mentioning the heat shield at the spare tire and leaf springs but this was not my case.

 

I went back under the my 2020 Sierra today and combed over it inch by inch, plucking and hammering around. The heat shield at my spare tire seemed fine and didn't have any clearance issues with my GM performance exhaust pipes.

 

I made it up to the fuel tank and finally replicated the buzzing sound when I hit the plastic tank. I discovered the buzzing vibration sound was coming from the fuel tank heat shield on the driveshaft side. I reached up to the top of the heat shield and bent it at the top slightly away from the tank and the noise is gone whenever I hit the tank. I initially flexed it too far and popped out one of the plastic retainer clips. It was easy to reseat the clip. I haven't been able to replicate the noise for now but only time will tell.

 

Listen to the video clip to determine if your noise is similar. I have not come across a post about the fuel tank heat shield yet so I hope this helps some of you out.

[Rook126]

For those who are still having this heat shield noise issue, I wanted to let you know that I have not had the noise for the last couple months so I believe it is now resolved on my vehicle.