One problem related to gas recirculation valve (egr valve) has been reported for the 2010 Ford Flex. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2010 Ford Flex based on all problems reported for the 2010 Flex.
Original owner 2010 Ford Flex, ecoboost engine: sudden loss of engine power with shuddering and stall in fast lane; up hill while passing at speed, 60mph to 20mph in seconds causing near collision from behind. Engine would not recover, 20mph in fast lane with semi's and speeding traffic, no pull-off area. Clear dry day, temperature around 55 degree. Not the first time engine shuddering experienced, but the most dangerous. Always occurs during acceleration (pulling out in traffic or passing, etc. ). Began to notice loss of power, whining and grinding noises from turbos about two weeks ago; subsequent catastrophic failure of both turbo chargers with billowing black smoke and oil dripping from exhausts. 38k miles, garage kept, all service points maintained, driven like grandmother since new. Fist the rear brakes locked up while driving at 18k miles, now engine failure at 38k. Do something ntsb before these vehicles kill someone!.