GMT 900
Well-known member
I promise, scouts honor...Whoops, I wasn't ever a Boy Scout.Oh I don’t believe for a second that you are “done.” LOL.
So, I went back and forth with Terrence last night. Basically, the summary of his argument is this: he sees carbon buildup to be an engine design issue. He doesn’t believe DI or port to completely negate the issue, nor does the PSI from the high-pressure rail system. He also doesn’t believe the new “modern synthetic” oil reduces carbon buildup either.
He also owns a 2013 Ford EcoBoost and that is one of his examples of poor engine design.
IMO - the carbon buildup issue resolution is two-fold - high-pressure direct injection atomizing all the fuel. This prevents any leftover fuel from being an issue. The second resolution is the new oil with additives meant to reduce carbon buildup.
It seems to me carbon buildup will happen. It is just impossible for it not to with an engine’s combustion and the need for better performance and emissions - GDI.
The question then isn’t about IF it will happen, it is to what extent this happening is a problem. I tend to believe the engine designers have done what they can and the oil company scientists have done what they can. I also believe this issue will fade away in future years with future engine tear downs showing either clean or relatively clean intake valves.
I remember when I did the tear down story on the million mile Tundra. Those intake valves had very little to no carbon buildup on them. That was a 2007 truck - https://www.motortrend.com/features/million-mile-tundra-the-tear-down/
Yeah, port injection only on that Tundra and the Ford Tech in the video I linked showed a port only engine being very clean. I can imagine this may have happened in the days after PCVs were mandated (1960s) and detergent gasoline wasn't common; wonder what the back of my '75 Buick 350's intake valves looked like in the early 80s?
https://ftloscience.com/chemistry-of-detergents-in-gasoline/
The manufactures and oil companies worked together to make sure the surfactants didn't harm the engine, so maybe they can team up some more to add something to the fuel to resist fuel dilution in crankcase oil.
GDI is not going away anytime soon, so it may be something where the old "Tune-up" is now the periodic walnut shell blast.