Hello community In my SL400 (2017: 65000Km) I have a metal jauling in the partial load range, which can be heard in the ignition clock quite high frequency and unfortunately also very loud… (especially loud when right or left of the car is a wall (sound reflection) or something like that. The sound is best to describe as if one stirs with a snow broom in a large aluminum bowl, whereby the stirring is interrupted by an igniting synchronous ticking. 30Km/h in the 3rd gear, just in traffic with flow. If you stop, the sound is still running for about 1-2 seconds and has disappeared. With a short gas shock, it is easy to hear with sinking speed and at stand gas speed again disappeared. When giving gas or in normal driving there is nothing to hear. The SL drives completely normal, the sound is also normal except for this noise! It has nothing to do with the circuit or the driving mode because it can be heard independently of it. In my opinion, the sound is ignition/exhaust synchronous and behaves like a control or as if there is a control behind the noise. Had the SL with the MB service, but it did not detect anything! In an exaggerated way, MB says that everything that has to do with noises is measured with closed cover and windows. Then, however, there is nothing to be heard. My question to you: Is there a dynamic control process on the SL 400, which may have to do with the exhaust system (bracket control, catalyst or AGR) and can lead to such a sound problem? Does anyone have technical vehicle information on the basis of which they can get a modest overview? I only think further if I say MB where the problem is. The weather gets better and my SL hears itself in the 3 0-Zone like a large aluminum bowl on… Excruciating… ?… Thanks for your contributions Hans