My car (2016 CLA 250 with ~16000 miles) started exhibiting a weird noise around February 2017. I didn't pay too much attention to it until these two months. I noticed it was not a one time thing, so I brought it into my dealer. The first time I brought it in, they didn't find anything wrong. A few days later, it did it again, so i decided to record it to show them. I brought it in a second time and the service advisor thought it was a heatshield issue from watching the video. The mechanic did not agree, but he took the car to check for issues. A few days later, the service advisor called me and said there was a sheered bolt on the heatshield which they replaced. This was on September 9th. Today, September 17, I experienced the noise again.
The noise happens as I am making a 90-100% right turn after I cold start the car, sit until RPMs drop until ~800RPM, and drive straight a car's length worth of distance. The car has to be sitting in my garage, engine off, for at least a day, for the noise to occur. Based on this last condition, I am assuming it is temperature related, as in, the car needs to cool down to ambient for the condition to occur. I've tried, immediately after the car makes the noise on the turn, to back up and drive forward following the same path, but it only happen that initial time. Below I have videos and a picture of the travel.
My garage is right in front of that grey car. So I have to drive the distance of that car and make a right turn out of my garage.
I do not intentionally try to get the noise to come in, so I have not tested other conditions,