This week we saw a client’s stunning Mercedes 540K come in for a running fault. We started looking at this fault a few months ago but the starter motor failed and due to some difficulty getting parts this held up proceedings.  Not being able to get parts off the shelf is no problem for us, we had the part we needed made by a specialist machine shop. Once we got the starter motor rebuilt and refitted we were able to look into the original fault of the Supercharger staying engaged constantly. The Supercharger should only become engaged on full throttle and should be only run for 30 seconds at a time.