leomio85

Rattling, clicking, chattering .... whatever noise you'd like to call it. I was having this issue that initially cropped up while going over imperfections, but soon started getting it while driving over even smooth roads. It sounded like it was coming from the roof of the cargo area, but turns out it's from the foldable floor of the cargo area. I suppose it's from touching the plastic under tray that causes the noise. I guess the CostCo hauls eventually warped the flooring a bit to cause it to eventually make contact over time. I initially remedied/honed in on the issue by driving around with the flooring folded up and the noise went away. Went to Michael's (craft store) and found some adhesive backed foam sheets and cut them up and lined some of the areas where it seemed like the noise was coming from while knocking on the flooring. Put her back together and drove around for a couple of hours while running errands today and it was completely quiet. The pano sunroof still rattles when going over bumps, but it's distinctly different from the rear cargo rattle.

Hopefully this helps someone. The noise was driving me bonkers.

Burger Steak & Eggs

I had the same problem. In my case it was the little rubber bumpers on the foldable thing.

DJA123

Got it when cold. The search begins...

leomio85

It probably is those small bumpers. Pretty sure they're plastic, hence why there's the noise. Acura put some felt lining on part of the undertray of the flooring, but not on all of them, which is weird. They may have rubbed thru tho, causing the noise to occur after some time. I cut pieces and lined them around the plastic tray part. Started with the plastic bumpers but just decided to start cutting long pieces and doing it between the bumpers. Whacked the area around it with my fist until I stopped hearing any rattle. Drove it around and didn't hear it at all with the floor in place. If it crops up again after hauling stuff in the back, I'll go back and get the rest of the bumpers or perhaps just double up the areas that I lined already.

BoBoish

Among the greatest things ever invented are adhesive-backed felt sheets. I've used them liberally throughout my car. You can pick it up at Hobby Lobby, Michael's or any other craft store for under a buck a sheet.

DJA123

Agree. I'm a woodworker and have a collection of little sticky felt doodads. I just hope it's that simple and not something behind something, inside something, underneath something.

I've also noticed some clicks and ticks in this car from adjacent soft surfaces. It's like the surfaces "tick" as they touch and release.

I hate interior rattles and noises.

DJA123

I removed the folding floor panel and the noise seemed to disappear. I then noticed the floor hold down clips nearest the seatbacks rattled in their slots. Hard to describe, but I pulled thin wire under and around the top edge of the clips to snug them tight. I then covered all the plastic bump squares with thin felt dots. When I replaced the floor panel it seemed quiet and more resistant to movement. I'm confident these tweaks are the fix. Thanks for the shortcut.

leomio85

Glad it worked out. The noise was driving me nuts. So glad it's gone and driving the RDX is far more pleasurable now.

Wolfsoks

I’ve had similar rattling issue for months in my 2019 Advance AWD. The rattle seems to be at its worst after the right rear wheel hits an imperfection in the road. I’ve taken to my dealer four times and they are adamant it is due to a spare tire compartment issue. But they cannot solve it. They’ve replaced parts, added a foam seal, nothing works. They claim my car is the only one they’ve seen with a rattle and do not feel they can fix it. They have explicitly said it is not the trunk floor compartment. Has anyone heard anything from dealer directly on the rattle? Going to try felt backed tap around the entire edge of the compartment but I am skeptical. Thanks

DJA123

If we're talking about the same cause, my report above absolutely helped me. There is play in the cargo floor, but it's relatively easy to fix.

Try taking it out to see if the rattle stops.

Yotrek

any pictures where exactly the noise coming from?

DJA123

Based on the OP's suggestions, I made several changes, so I'm not sure of the actual source. I strongly suspect it was the male/female clips behind the rear seats that hold down the back edge of the floor panel. The clips themselves rattled. The soft felt dots might help too. I put those on the existing plastic "cushions" underneath the folding panel. There are a lot of those. If you remove the panel, these will all be obvious. Fold down the rear seats for easiest access. (The clips are pulled straight up to remove)

russianDude

wow, glad I found this thread. I got similar rattle over uneven surfaces shortly after getting TSB for comm errror. They did have to remove cargo lining, and it looks like technician did not secure plastic insert that is right behind the seats under a strap.
its a black plastic insert (9-10” long) that has clips. It supposed to be securely fastened, I guess they forgot.
I pushed it back in place, and car is quiet again

DJA123

Yeah, this was a real annoyance for the first few weeks. I don't know if my car had a bad batch of clips or not, but the way they loosely engaged made it impossible for them NOT to rattle. Since this isn't a widespread complaint, I assume most cars had better clips.

Once again, this makes me think there is a lot of variation in component and assembly QC.

russianDude

I put a little velcro tape next to clips to minimize the movement. But main issue was that plastic insert was left unfastened.