My wife's 2014 LTZ make a rhythmic noise when the brakes are applied lightly. If the brakes are applied more forcefully there is no noise. This has been going on for a while. The car was Pa. safety inspected in February and the brakes passed inspection. The noise was occurring at that time also but the car is not driven during the inspection. So the pads were good enough to pass inspection but there was still the noise when lightly applying the brakes. The rotors were turned when we bought the car with 27,000 miles on it. The car now has about 44,000 miles. I'm thinking maybe the rotors need resurfacing or replacing. May need pads now also. I don't think the noise is a suspension issue. The frequency of the noise coincides with the decreasing speed of the car when applying the brakes. It's not a scraping noise like metal on metal. More of a groaning noise. I hope I'm describing it well enough. What do you folks think? I'm going to take it to a shop in another week or two. But I always try to have a handle on what is going on before I take a car in. The shop is new to me because I have only lived in Pa. for a little over a year.