Carbon build up
 

Ok, if want see what carbon build up and IMO lack oil changes does too turbo/direct fuel injection engine does to piston rings. Here good video.

https://www.youtube.com/watch?v=VhR2kMIr3NA

IMO GDI turbo engines may be new junk engines surpassed 1980s designs. IMO engine with fuel injection going down intake above valves don’t have severe carbon build up due to valves getting sprayed by fuel mist going to combustion chambers.

This Is My opinion I would not skimp on oil changes intervals with GDI (direct injected) engine especially With turbo which generates more heat and pressure on top piston ring groove.

IMO 2017 vehicle not that old to have major engine damage (but don’t know history?). By all slug buildup IMO looks like oil change intervals was too long? This all my opinion others may have different opinion which will probably not change mine.

My Toyota Tacoma comes with free oil/filter change every 10,000 miles, which I feel is too long. I will pay and have it changed every 5,000 miles.

I would be following up on those free oil changes make sure they did it. I have horror story from OKC about a dealership free oil changes, it wasn’t Toyota dealership.

The sad part Toyota will refuse to pull your free oil charge before 10,000 miles.
These oil intervals stated in manuals are a joke.

Agree - Using a Top Tier fuel and going no longer than 5,000 mi between oil changes on the small direct injection turbo charged engines is highly recommended.

The manufactures oil change interval is to get energy credits at the expense of your out of warranty engine life.