Thumping at my feet?

Starting yesterday every time my driver's side drops there is a weird thump at my feet. It literally feels like someone is tapping my weathertec digifits from the bottom every time the suspension articulates. Has anyone experienced anything like this before?

The truck still drives 100% normally and seems fine except for this tapping in my feet.

I can't help but wonder if somehow the bolts on the top of my 1500s got loose when I hit a pothole yesterday although that really makes no sense considering I did the swap over 6 months ago and have wheeled and driven the truck a ton since then.

Edit: I just had another scary thought- could it be my oil filter rolling around? I had my oil changed with full synthetic yesterday at some quick lube place since I didn't feel like rolling aroun in a foot of snow to do it. Maybe they left the old one sitting somewhere and its now rolling around on the fire shield? I would have seen lights come on pretty fast if the new one fell off right?

 

Pop the hood and see if your oil filter is in place. If so, then that's not the problem. I felt a similar thumping at the feet too once when the truck was completely covered in snow and ice. Once it thawed in my heated garage the thumping went away. Figured it was ice or something.

 

Yeah I have that in mind too, and that is the most likely the case. I can see the new filter, but I can't tell if the old one isn't rolling around somewhere.