Carbon build up, Toyota vs others?

[nielshm]

The video shows a 10.000 mile Golf R. Pretty bad carbon build up, despite premium fuel and additives. 

The Golf only has direct injection. 

I know Toyota has both port injection and direct injection, that should remove this issue. But does it? Has anyone seen photos of Toyota Corolla intake manifolds or valve, and are they nice and clean? 

Does all of Toyotas newest engine have this dual injection system? Are there any Toyota engines, that only has direct injection, and could look similar to the VW Golf? 

 

[TonyHSD]

Hi, you don’t need to worry about carbon build up on dual or port injection, this is only about direct injection engines and does not matter what make it is if it’s only direct will suffer same thing. I have seen on my car after 130k miles 1.8 hybrid with port injection clean as new, not shiny but white-greyish colour. 👍

[Gray86]

That Golf R was a US model which doesn’t have port injection. UK cars had port injection from 2014-2019 (removal coinciding with GPF fitment).
 

Even with port injection you still got carbon buildup on the inlet valves on the UK Golf Rs, to a lesser degree - the spray from the port injection doesn’t quite hit the valves due to swirl flaps being in the way. 
 

turbocharged petrol engines get a lot of blow-by which forces gasses (oily gasses) through the PCV system which ends up on the valves (turbo seals also let oil into intake). 
 

The potential issue for Toyota is carbon buildup on inlet valves through the EGR system, however this wasn’t really an issue on the GEN3 Prius / Auris so shouldn’t be an issue for current generation vehicles (EGR carbon buildup still an issue)