Originally Posted By: camelCase
Diesels run at slightly higher temps and don't have an vacuum acting on them. This is one of the many reasons diesels don't have the issue. Plus... [censored] EGR designs in gasoline DIs.
Guess you are not up to speed on diesel designs since EGR, DPF, SCR, and CCV have become part of the mix since 2010. The CCV allows, even with the filtration they have, some oil residue into that intake manifold. The EGR on diesels is notoriously laden with soot from the exhaust. Now combine those two things flowing past the intake valves and you can get a vivid mental image of what is going on. Yet, these engines do not undergo regular intake cleaning and last upwards of 1 million miles. Ever wonder why the oil is black almost within a few miles of a fresh oil change? And that is what is getting sucked up into the CCV filters and some is getting thru to combine with the EGR coming into the intake.
In relation to this, the DI gasser intakes would be relatively clean. Gas engines are not notorious for generating prodigious amounts of soot like diesels. This is why, at least on the surface, that putting a lot of worry into intake valve cleaning on a gasser seems like evidence of an inflamed paranoia gland. It is something to think about and consider at some point, but sure not something to lose sleep over.