I have about 170k on my Saturn Sl2, but a rebuilt engine with about 80k on it. About 1/3 of the time when I brake, i hear a strange sound that sounds like metal on metal. I think it is coming from the front, possibly from the driver side, but it’s hard to tell… I thought it could be a stuck caliper (they were in rough shape anyway) but the sound came back after I replaced them. I also have changed the pads and the rotors. it sounds like a lower pitch version of the sound a leaf spring makes when you drag it across concrete. Anyone have any ideas?