One problem related to automatic transmission has been reported for the 2008 Mercury Mariner. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2008 Mercury Mariner based on all problems reported for the 2008 Mariner.
My 2008 Mariner automatic transmission will not shift properly when cold (winter) or too hot. This also affects the idle when stopped. When vehicle tries to shift up, it will only shift if I let off the gas, then the transmission slams into the higher gear. The vehicle will hesitate when trying to use passing gear to pass other vehicles. This has led to some close calls/near misses when trying to over-take vehicles. Ford says they know there is a problem with this make/model but have not issued a recall. Ford says they can fix it with my money.