Since we are talking about changing too early, what about these comments from Pitzel in another thread ?…..
Originally Posted By: pitzel
The key with a direct injection engine is to not change the oil any more frequently than the owners manual or oil life monitor demands (some people think they're 'helping' their engine by changing oil more frequently than spec -- this is wrong, especially for a DI engine!). And pay particular attention to the oil actually used. DIY or physically observing the mechanic/technican pouring sealed bottles of the properly spec'ed oil is best, if you can. Don't just blindly assume the dealer or the quickie lube will use the appropriate, specified lubricant, rather than low-bidder bulk 5W-30 dino that might not meet the latest specs on volatility.
Most of the trouble reported with DI engines and oil, particularly the notorious intake contaminant occlusion issues, has been related to either the use of improper lubricants (either out of ignorance, or out of profit seeking motives by less-than-reputable maintainers). Or the overly frequent changing of oil by good meaning people stuck on maintenance practices more typically recommended 30+ years ago. Old habits die hard, but with DI and the lack of fuel vapour diluting the recirculated crankcase fumes, intake contamination is exacerbated by those extra oil changes.
Originally Posted By: pitzel
The premise is that the intake occlusion/contamination issues are mostly caused by recirculated volatilized products of motor oil depositing on intake components as they mix with fresh intake air and are drawn into the cylinders as part of the intake air charge.
Motor oil volatility is at its peak when the oil is brand new. And declines over time as the oil is in service and is subject to repeated distillation inside the engine under the vacuum imposed on the crankcase by the PCV system.
So to fix the problem, simply minimize the volatility of the oil. By both selecting the least volatile oil as possible. And using that oil in its least volatile condition -- when its been in-service for a while, minimizing the exposure to 'brand-new' oil which is susceptible to higher distillation loss.
In Europe, and even in the manufacturers' labs in the USA, the problems could not be replicated, as manufacturer-recommended maintenance practices were adhered to in the test environment (over-maintenance isn't generally a usual test case!) and the actual European end-user environment. A few years back, I personally did a meta-analysis, on BiTOG, of a lengthy car-proprietary non-BiTOG forum thread where people were complaining of issues -- there was a very strong correlation between improper maintenance practice (too frequent oil changes) and intake contamination.
Also, manufacturers have tightened the volatility spec severely over the past few years in response to the DI intake contamination troubles. Ostensibly because controlling volatility is a significant component to the overall 'solution' to this problem.
Some people have had decent luck with "catch cans" and other inserts to the PCV/breather system. If there's no adverse affect on instrumentation or the normal characteristics, this can be a valid solution albeit requiring additional maintenance. However, it really doesn't address the root cause of too much, and too poor of quality motor oil causing the problem in the first place.
Original BITOG Thread
