With direct injection I am aware that the intake valves can be prone to carbon build-up given the lack of fuel washing over them. Over in the US it seems fairly common practice to use Sea Foam spray applied downstream of the throttle body as either a preventative measure or to clean up already-fouled valves. The product doesn't seem readily available in the UK though from what I can gather, aside from a couple of importers on eBay that is.

My question is twofold: 1) Some engines seem more prone to issues than others - does anyone know where the 1L Ecoboost (noting it being a fairly new design) fits and whether problems are being seen?, and 2) if there is a potential problem here what have others been doing to mitigate it?

My experience is that the 1.0 and 1.6 ECOboost do not suffer from excessive carbon build-up on the intake valves. Last Year I inspected both my own Focus MK3  1.0 ECOboost and the Focus MK3  1.6 ECOboost of my parents using an endoscope. On both engines the intake valves were nice and clean and did not have any signs of excessive carbon build-up. Unfortunately I did not take any pictures during inspection.

 

Most of the ECOboost excessive carbon build-up stories that are written on USA websites and forums apply to the 3.5 V6 ECOboost and the USA 2.0 ECOboost. The USA 2.0 ECOboost is a different engine than the European 2.0 ECOboost.

 

Thanks Wilco; that's good to know. I did think about sticking a scope in and taking a look.