Just wondering if anyone has had a problem with temperature Gauge going up to the red after driving for 30 minutes or so. It will go up for a few seconds then back down to around 90 or so and then up and down . No warning lights come on and don’t seem to be overheating as hood not hot . Had it checked by mechanic (not Mercedes) and levels are good and no leaks and could not find anything. I am going to take it to the dealer because nervous driving but just thought I would see if anyone had the same problem .