2007 Prius w/ ~90,000 miles. So my wife was driving home and reports she hears a thunk of some sort, and then a scraping noise coming from the front of the car. She drives it home and I take a quick peek. Nothing dragging underneath, sounds like it's coming from the tires, so probably brake-related. But here are some additional clues: when I reversed down the (very short) driveway (at very low speed, <5mph), I heard the scraping. I then put it in D to go forward, again at low speed, and heard the scraping and then something went clank, like something was shifting in the other direction. Whenever I change direction, the clank sound and more scraping. Also: when the car is off and I'm gently rocking it back and forth, I hear squeaking, like springs of a bed. Any ideas? Also, anyone know of a good shop in the Dublin/Columbus, OH area? Thanks!
Probably the noise is due to a stone stuck in the brake shield. It has happened to others. Not a big deal and any garage mechanic can get it out for you. JeffD
I drive sand roads all day, this sounds fairly serious for a rock (especially the clank) , usually rocks disappear driving a few feet in reverse. Suggest the 'back roads' , nothing fast, on the way to the mechanic if you don't take off the tire closest to the sound and examine further. If you want to take apart the brakes, check out the threads on brake changing for more info, the system is a bit more complicated when taking apart the brakes than most cars. Then again , a rock may be just wedged inside the dust shield like jdenenber suggests, and a long screwdriver could remove it.
To follow up on my original post, I finally got it to a shop today, and it turns out it was a tire weight which had managed to work loose and get jammed between the rotor and the... something. I can't remember. The mechanic who took care of it said it bent something, but he was able to bend it back. I was super surprised when I got the bill -- $0.00. They said it was a pretty simple fix and they didn't charge me anything for it. That doesn't happen very often! So if you happen to be looking for a good car repair shop in Hilliard, OH, check out Auto Emporium on Scioto Darby Road.