Just to throw my $0.02 cents in is the only reason any of you will experience Valve Build up in these newer generation Eco Boost Engines, as already stated, Is due to the Direct Injection. Before it was main stream the only "Main" build up was Pre Injector nozzle, where the fuel is not cleaning the back of the valve off. And had a TREMENDIOUS amount to due with not maintaining good engine oil or changing it regularly. The entire gimmick against a 5000-7000mile oil change has always shown to be wrong in multiple studies and test across more then just our country.
Direct Injection Engines have a fail safe in this department and that is a spare injector that Ford used to spray fuel into the intake as a "Self Cleaning Procedure" but early on was shown to make emotions too high while in the cleaning process so most have been tuned down ( Low Cleaning Effects ) or completely deleted for the USD market. I got the chance to work at a machine shop for a number of years rebuilding engines and we contracted with local dealerships for multiple machining jobs. So I was sent to some EcoBoost and Ford Training sessions because they were free, and why not! I have a few books on this and ill see if I can dig them up to show you how they are training shops/technicians in these scenarios and what process they want when the build up becomes a drivability issue. But hands down. There all time immediate fix to this issue is only one option. REPLACE the intake. Witch in my opinion ( Aside from cost of manufacturing, obviously ) is why mainly all new intake manifolds are plastic. They have a TSB for older generations to just change the manifold and ship the customer with no cleaning process of the valves.
Most shops are resorting back to the walnut blasting services that were very common in the mid 2000's. Witch is a GREAT process and not that costly. Using a higher grade fuel is a HUGE debate, and always has wives tales from the 1950's that stuck with people. But for me. In California. We have 3 fuels, 87 / 89 / 91 octane. I religiously only use gas stations that are busy and well known ( Chevron , Shell , Etc.. ) and ONLY use 91 Octane in everything I own. My daily driver ( 2001 Toyota Corolla AE101 ) , the wife's Bronco II ( 2.9L ) , Our 2015 Audi SQ5 ( I would use higher if I had access for this car ) , and many more I own but wont explain on haha. Without a doubt its just what I do. And onto OIL! Every single car runs 2 oils with one exception for the Audi. That's IT. Ams Oil for the classics, with a bottle of Zink. Chevron 15w-40 Oil for the Diesel ( 7.3L OBS Ford ). And LiquiMoly for the Audi. And they all get changed at 3,500 miles. No exceptions. No excuses. Oils get absolutely beat down in modern engines being pushed threw small passages and VVT solenoids along with High Temp to Cooled temp very rapidly. Almost no oil can handle that abuse, Let alone for 7,500 miles + depending on who you talk too. Your PCV system is recycling that oil vapor trash back into your intake. The longer you go, the worst that vapor gets.
My take on the EcoBoost line up is nothing but pure love. Its the most adaptive, yet simple engine platform on the market. But I am basing my first statement off of a few years back, on top of the fact its 2am here after just working about 18 hours HAHA. So some stuff could be wrong about Ford's cleaning process on these until I can back it up with what I'm pretty sure I remember reading. Ill find some of those class books and post some updates when I get the chance.
To end this useless little rant I went on Haha, I will address the cost of fuel with the same thing I ALWAYS say. I do not look at the price of fuel nor worry that I go out of my way to buy better fuel for more money. Because at the end of the day, what are you going to do, NOT buy it ?
Current California Chevron Fuel Cost nearest me ;
87 octane : $5.50
89 octane : $5.60
91 octane : $5.70
Diesel : $6.50
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