Hi guys:
I have been thinking that direct injection on the EcoBoost and other engines from all manufacturers was the best thing since sliced bread (aside from the issues of higher fuel pump pressure, etc.).

However, I have been poking around the Internet and there is apparently a generic problem with direct injection engines where the intake valves get gummed up with PCV (crankcase fumes) and EGR gunk. Traditional port-injection engines have gas and it's additives moving over the intake valves and keeping them clean (or mostly clean), but with DI engines, this doesn't happen.

It looks like Audi and VW have been having the most serious problems. If you google "direct injection engine intake valve deposits" you will definitely find a whole bunch of links on the problem. And some really ugly photos of intake valves...

Toyota, I think, has a partial solution in that they do use a separate injector in the intake port (as well as the one in the combustion chamber) that does some of the work and intake valve cleaning.

Just pondering whether this is going to be any kind of issue with the EB motors. I'm guessing that as an engine ages and has more blowby, the PCV valve deposits will get somewhat more problematic.

Just thinking (or worrying) in advance,
George