 After having multiple check engine lights come on while driving on the Interstate, I've had it.  Contacted Premier Diesel and Auto in Mansfield TX who told me this 6.4 engine is horrible.  They advised me to sell or trade it.  The engine was made by International not Ford.  They said the engines just "blow up" and they have multiple trucks sitting on their property that need new 6.4 engines.  Just bought the truck used in February and having to take a loss to trade it in.  Wish I knew then what I know now.