SLK 320, E320 4_M
I am experiencing a sound similar to what might be expected from a loose or vibrating muffler or cat. It occurs only when riding over a rough surface such as expansion joints in a parking garage. I have had my mechanic check out the problem, but the muffler or the cats are not the problem. Eveything under the car appears secure and tight. Has anyone experienced the same problem or have suggestions what might be causing a pinging sound?