Fair enough questions
Engine oil does three things
It cools, it lubricates and it cleans and holds contaminants in suspension.
It all started as 15w40
And it was not a starvation issue
It was a failure of the oil to continue to do its three functions
The problem is not what the gasifier did to the engines but the oil and it’s results destruction of the engines
Both engines shut down started and ran
Both were stripped for an internal inspection and scrapped because of the damage
HI All,
I have been researching the most modern use for the last 10 years of Gasoline Direct into the cylinder Injection systems.
There is actually some engine sooting and carbon builds up problems with GDI just like when using woodgas.
This topic seemed the best to put some of this prevent and clean up information onto.
This video gives a good brief of why the manufacturers have changed to GDI versus the previous Port injected. Explains a bit the Positive Crankcase Ventilation system as the source for most of the carbons and soots. What can be done. What will not work to prevent, or clean.
On youtubber “wildgeese” channel. Direct Injection: Problems and Solutions
Another video this time on Engineering Explained channel; the Three problems With GDI:
Some the same info but with the claim that soot in oil causes increased timing chains pivot-pins wear.
In both cases they are saying use the latest grade specification of oils for anti-wear and increased oil dispersants. Then change it out to carry out all of the oil suspended carbons, soots and gasoline contaminates.
They both show the engineering forced engine testing to qualify for these new standards.
I have family now driving for a few years different GDI vehicles. My wife decides to get one last life-time new vehicle it will be have to be a GDI system.
Regardless of gasoline/diesel/gaseous IF you minimized internal engine wear with oil change outs the blow-by into the crankcase will be minimized.
Contaminated loaded oil, makes for sludging build ups. Clogging.
You do not pee or poop for a few days and you will get very internally polluted sick.
S.U.
Steve,
That video doesn’t want to play on my computer. Maybe check the link? Some channels wont allow playback on sites other than YT. (lost ad revenue) Maybe just post the channel name, video name and we can search it ourselves. 
Edit: I think this one is it?
and:
O.K. after watching many, many videos on valve and ports cleaning for carbons building up I focus on these two.
The first more re-explaining the problem and a kinda’ sorta’ manual cleaning versus walnut media machine blasting cleaning.
The second also a manual cleaning but using spray-can chemicals, brushes and wipes.
Yeah.Yeah. Many video’s will say you MUST manually scrape to get all of the cooked on carbons off. True. To make them “Professionally” cleaned. With photos of before and after.
You are DIY seeking good-enough.
And many videos will say hot engine running with a patent spray engine running vacuumed into to the upstream intake will be good enough. Maybe. Maybe not. Washing the whole intakes on port injections intake service would often washed cruds foul out the spark plugs! Only do this right before you will be replacing the spark plug for age. And most all sideways V-6’s are remove the upper intake to get to the back three spark plugs. Don’t easy-spray and make a bigger problem for yourself.
Here is the back-to-the-future sadness. Back in the 1960’s when I started auto wrenching it was common on some engines to have to cylinder heads remove and de-carbonize every 40-60,000 miles because of no longer able to use regular grade of gasoline. Or; too many hot run-on problems after turning them off.
When the lead was taken out (always at least half of the combustion chamber and valve faces build-ups . . . grey deposits . . . insoluble . . . scrape, scrape, scrape) that services needs went away.
So now this past drudgery has come back.
Ha! We balance of use peaked in the mid-1990’s with simple port fuel injection and OBDI in my experiences.
Wifie ever upgrades to a newer vehicle with GDI . . . or a relative show up with long term GDI misfiring problem then I’ll be angle drilling spray-in holes pointed down to the valves into their plastic intakes. Threaded and screw plugged. Hot running, preventive spray clean once a year, every 15K.
S.U.