2001 Other Mercedes Benz Models ML 430

The first thing that strikes me is a catalytic converter. The cats like to make rattling noises at idle and low throttle accel. To test, let the vehicle cool down, then get underneath the vehicle and hit the cats with a hammer or equiv. If you have a bad cat it will rattle when you hit it. If you notice a rattling from the cats then replace the corresponding cat. Always check with mercedes benz to see if it can be warranty also - If its not cat related, please give a more specific noise description in order to help us help you.