Here is a technical service bulletin on Flex Ford vehicles from 2010-2014.

Some 2010-2014 Ford Flex vehicles equipped with a 3.5L GTDI (gasoline turbocharged direct injection) engine with an aluminum valve cover may exhibit excessive oil consumption and/or an excessive engine oil smoking condition from the tailpipe at idle during normal engine operating temperatures.

Remove the PCV valve. Inspect for oil in the crankcase vent oil separator through the PCV valve opening. If you note the presence of oil, more than a slight vapor, replace the right-hand valve cover and replace the crankcase vent oil separator. Drive the vehicle at normal operating temperature for 20 minutes at constant highway speed to remove any oil residue from the catalytic converter.

https://www.autoserviceprofessional.com/articles/9...