We purchased a CPO 2011 Mercury Mariner Premium in October 2013. The first time this incident occurred was when we had the car about 2 hours. What happens is after driving for a while at a high-rate (usually about 60mph or higher), I gradually slow down as I get off of the freeway and start heading towards our house. Once I get into the subdivision, as I am coaxing, the car will lurch when it is at about 20mph. This also happens if I am on the toll road and then slow down to pay the toll then somewhere around there or when I stop for my turn, it will lurch. I took the car back to the dealer within the first week and the mechanic and I drove the car for a while and of course, it didn’t happen. He said there was no way for him to know what was happening unless it happened when he was in the car. I was actually put off because I asked if we should keep driving or take it back to the shop and he said “well, you know I don’t get paid for test drives”. seriously? lol
Anyway, they checked to see if there was an update on a module or something? He said there was (again, said he didn’t know if it was related to what I was experiencing). It is still happening. We previously had a 2009 Ford Escape and got pretty good gas mileage. That car was totaled (fortunately no one was injured…my newest teen driver lol), and we had hoped to get as good gas mileage with this Mariner but no. Also, in December (2 months after we got the car) the “check engine” light came one. I scheduled it for service for the following Monday (it was Friday) and later that day, the car kept dying. We had to have it towed in. They repaired that problem and we hoped that it would solve this other issue, but it did not.