mbfoup

I was wondering if anyone had experienced this but sometimes (rarely though) when I am stopped at a traffic light (still in gear but with brake pushed) the engine falls momentarily below 500 RPM (with some vibrations) and then recovers. My E550 is new so I suppose this is perhaps normal until the engine has more miles on it. Or perhaps not. Anyone have seen this before? Thanks.

Spirit Crusher

That doesn't sound right at all. I would get it checked out immediately, especially if you purchased the vehicle.

mbfoup

Was due to faulty exhaust O2 sensor (and engine light on). Fixed by MB.