See if ford will buy you a new head. When they say no, ask them how to clean it. When they answer, show them the part of the manual where they dont suggest chemicals beyond what's in the manual. They've boxed themselves in on this issue. They've admitted There is no way to clean them besides blasting with media without risking damage to the turbos. This is the reason they went to dual fuel. Since walnut blasting isnt in the workshop manual it is not recommended by Ford. They effed up big time on this and I would be shocked if there isn't a class action lawsuit before its all over. Lots of aging Ecoboosts on the road now. Use their words and policies against them. I'm a Ford guy but BS is BS.