Nittany08

I have a 2016 Acura RDX AWD. When hitting potholes or recessed manhole covers or any other "sharp bump", but not gentle bumps, there is a hollow metal rattling sound. This sound is coming from the driver-side rear tire area and is most prevelant with the windows down. It sounds like something hitting a heavy gauge heat shield. If the passenger-side rear tire hits the same types of bumps there is no noise. Which leads me to believe it is something within the tire/suspension on the driver-side rear tire. I also had it in the garage and they were able to replicate the issue but couldn't find anything wrong

What I have done already (with no success):
- Tightened down spare tire
- New tires
- Alignment (shop only adjusted front as the rear was within tolerances)
- Re-torqued suspension components
- Checked shock for leaks (none found)
- Disconnected/removed sway bar end links and problem persisted

fcostantini

You may want to look at TSB 16-059 - Pop or Clunk from the Rear Suspension in Cold Weather.

http://www.urvi.net/forumfiles/SB/B16-059.PDF

Nittany08

I had looked at that TSB, but this occurs even on warmer days (like today when it's 70+ degrees) and it's more of a rattle than a pop/clunk

firstRDX

I had the same problem on my 2015, it drove me crazy. I thought for sure it was the spare tire or the sway bar links but turned out to be the rear shocks. They don't leak or show any signs of wear, something comes apart inside them.

Nittany08

Well after multiple mechanics looking at it and giving up and ordering replacement shocks I discovered what the issue was. While removing the old shock I was trying to manuever the lower end of the shock in the LCA to get it out when I bumped it into something and that something moved. I reached into the little "hole" in the LCA where the shock attaches and I pulled out a freaking brake pad. It must have fallen in there somehow when I did the brakes this past winter and I didn't notice I was short a pad when I cleaned up. I reinstalled the existing shock and drove it down the street and the noise was gone. I received the expected "you're an idiot" from the wife, but I now have $150 back in my pocket as I'll be returning the shocks. Just wanted to share this in case anyone else is an idiot like me.

Here is the "hole" the pad wedged itself into

hongthan

That's good that you found it earlier! I have replaced brake pads and rotors many times, I just can't imagine how it could happen?