Rear Floorboard Bumpy?

[ke5SS]

Today something strange happened and I wanted to check here to determine if this was in my head or not.

I got into the back seat of the truck and was walking from one side to the other to rearrange some items in the storage area. As I did this I had to put the seat back down (it was in the up position). Doing that required me to put all my weight on one foot. As I did this and closed the seat I could have sworn I heard a pop/thump under my foot. I put my hand on the floor and there is are some bumps in the middle section of the carpet. Nothing crazy as it still feels "supported", but it's not completely flat. Note: I have no floor mats back there at the moment.

Is it normal for the rear floorboard to not be level? I hit the floor with my fist and there is a large reverb sound in the cabin. As mentioned in other threads, I've been battling a water leak with wet carpets in the same area. I just wanted to check and see if this is normal as I'm worried the water damage may have caused something in the floor to deteriorate and give way under weight.

 

[Darksteel165]

Picture?

 

[ke5SS]

Attached is a photo I found with the location. I went back out and it visually looks level. It's not until you step on it and feel around that you notice subtle differences.

After putting some more weight on it I found a "soft spot" in the floor (towards the right side of the rectangle in that photo). If I step back down on it I can recreate the noise. It sounds like a popping noise and it seems like something is loose and not attached to the frame/floor, but whatever that thing is has some structure.

Coincidentally, I also noticed that by bass seems out of whack now. There is a bunch of rattling in the rear.

 

[Darksteel165]

Ill check mine in the morning and report back
I installed Husky floormats a while ago and I don't recall anything weird about the floor, but truthfully I didn't touch it that much.
I thought it all was flat.

 

[HSKR R/T]

Since there are the floor storage bins in the sidesz there's a good chance wire harnesses are routed down the middle. Usually they are inside plastic "tracks" with covers on the. You could have possibly broken one of them. Short of pulling up the carpet, you will never know.

 

[Darksteel165]

I checked mine today.
I notice i have a bump of some kind in that area. I can't notice it with floor mats, but if I put my hand I can feel it.
I didn't try jumping on it, but it's very minor. No noises either.