I have a 98 w210 with 170,000 miles. It has had many issues and now a new one has come up. I have had a slip or failure to shift between 2nd and 3rd gear for several months now. Just tonight as I was taking off from a light it would not shift, it stayed in neutral even when letting up on the brake and pushing the gas. After I shut down the car and restarted it, it began to shift normally again and was fine the rest of the day. I am fearful of what this may be. I recently changed the filter and fluid and the levels are fine. Would appreciate any guidance on this.