Yesterday morning, while traveling on the interstate, my check engine lite graciously lit up. My car began to act as if it needed to have a tune up. I knew this could not be since I had just had the MAJOR tune up less than 5k ago. I drove thew car about 160 miles and took it to a Mercedes tech. He examined the auto and replied that I had two coils that had gone bad. He also found that one of the new plat plugs had a brown burn at the base. My questions- Is it reasonable to have two coils go out at the same time? What could have caused the burn? Several times since I have had the S when cranking it up in the morning the auto has shook and acted as though it were not running on all 8. But usually within a few miniutes it would settle into its purr. This has happened sporadically since about the 40k mark. She now has 124k. Thanks for your help!!!!!!!!!