I backed into the steel bar from the dumpster at my apartment complex. The bumper doesn’t even have a scratch - just a minor dent that I think can be popped back out, but my sister says that the back tire is now making a noise. What could it be? The only signs of anything is the small dent and some rust/dirt like transfer that comes off when I rub it. Thanks.
What kind of noise? Post a picture of the wheel in question, and the underside of the fender, if you can.
The bumper is mounted on a couple shock absorbers so if you hit it hard enough to dent it, it may have pushed the bumper in enough to dislodge some of the plastic around the wheel-if its a plastic rubbing noise. Crawl under and make sure the shocks have allowed the bumper to go back in place and check around the wheel for any plastic hitting it. Otherwise don’t know. As fas as the little dent goes, heat it up with a 60 watt standard bulb trouble light, heat gun, or whatever to get it pliable, then push the dent back in place again. A lot of times you can just pop it back into position no problem, but heat it first.
The only experience I have with energy absorbing shock absorbers is with our 1995 Crown Victoria. My Wife drove the car 90% of the time and was rear ended twice. The shocks were one way and did not rebound. They had to be replaced. I always wondered why? It sounds like Nissan figured this out. When My 2002 Mitsubishi Eclipse was rear ended there was a small dent in the bumper cover. When I looked underneath the energy absorbing structure had done it’s job and was destroyed. OP needs to check this possibility.
Bumper shocks don’t rebound in order to prevent the whiplash effect.
I agree with your post. Fortunately, with a good exploded view drawing, the shells are pretty easy to remove (albeit time consuming). The OP might want to stop by the dealer’s parts window, pick up the rear bumper exploded view drawing, and remove the shell to inspect the energy absorbing substructure. There may be just enough damage to be causing a noise.