Like most, if not all modern engines, the Ecoboost 2.3 makes use of Gasoline Direct Injection, or Gasoline Turbo Direct Injection. One common feature of GDI (and GTDI engines) is an inherent buildup of carbon on the intake valves, while not a problem per se, all Ecoboost engines suffer from one common malady, a lack of Ford approved intake service to deal with that carbon buildup.
Why is there no Ford approved intake service? Simple, intake services break off the chunks of carbon, Ecoboost engines are swallowing that carbon and taking out turbos in the process...
GDI engines see carbon buildup at a faster rate simply because cool fuel (and detergents) aren't being sprayed onto the backs of the valves any longer, the fuel is being directly injected. Exhaust scavenging also contributes to the problem as waste vapor is being circulated and blown in the intake side during exhaust stroke to help clear the cylinder completely.
On YouTube, FordTechMakuloco sheds some light. Again Carbon buildup is NORMAL for GDI and GTDI engines, whats not normal is an inability to perform intake service.
So what are the solutions?
1: High Quality Gasoline- This will offer you the most complete burn during combustion
2: High Quality Synthetic Oil- Reduces the oil fumes that get caked on during exhaust scavenging
3: RUN IT HARD- Under high load the carbon will burn off. They call it the Italian Tune Up.
I'm sure Ford will have a solution shortly. But in the meantime there's a little incentive to get your foot in it