And, the 6.4 is not the worst engine Ford has ever come out with. It is however the first diesel that Ford has come out with to meet the current/future tough EPA demands.
So let's not blame Ford for the relatively small number of problems that have shown up. In the over-all vast number of 6.4 PSDs on the road, and given the total number of problems, it is a very small percentage of units effected.
There also is the internet which allows that small percentage of less than 100% pleased owners/want a be owners/ and owners of the compation/and gas powered trucks a venue to complain and blow little things into a much larger situation than the truth.