Two problems related to engine stall have 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.
Engine stalls out, while driving the car around town. Has occurred twice, separated by a few weeks. No warning, or engine trouble or indicator lights prior or after the event. Occurs while driving a low to moderate speed both times, about 30 mph. Car can be restarted immediately after and drives fine. Have had mechanics check fuel and air sensors and lines and find no obvious defects. Other Ford Flex owners report similar problem since 2009. Rumor is that replacing the throttle body corrects the issue.
Eco boost engine stall due to condensation of air from the cold air compressor in the turbo charger for the engine. Have had car serviced several times and dealer or mechanic can not resolve problem. Happen in freeway at high speed but has also happened in the street at 20 - 30 mph.