So does this mean that a catch can will help? I had one on my Kia Optima until, according to the dealer, it wore a hole in the a/c line.
I will put their conclusions here. IVD means intake-valve deposits.
* A standardized, vehicle-based GDI IVD test has been developed that is both repeatable and responsive to known additive chemistry.
* Higher engine loads lead to an increased rate of deposit formation.
* IVD formation in this protocol is an oil-related process, and the majority of the oil that finds its way onto the intake valves comes from the PCV system.
* The oil leaving the crankcase through the PCV system is whole oil containing additives and contaminants (not distilled base oil vapor which contains no additives).
* PCV gas flow in the intake manifold is inconsistently distributed among the eight runners of the manifold leading to the valves.
* Inhibiting the carbon-formation process lessens the rate of deposit formation on the intake valves.
* Oil consumption past the rings bring both additive and nonadditive elements into the combustion chamber where they are incorporated into the exhaust-gas particles.
* Particles found in EGR exacerbate deposit formation rate.
* Particles found in EGR appear to incorporate combusted oil additive components, engine wear metals, and ambient air contamination.
Gregory Guinther and Scott Smith
Afton Chemical Corporation
Note the conclusions I highlighted. They are saying that the main source of the intake-valve deposits is PCV. However, it's liquid oil (whole oil) coming through PCV as a mist, not evaporated oil (oil vapor). So, the amount of oil coming through PCV has nothing to do with the Noack volatility. saemobilus.sae.org/ content/ 2016-01-2252
Originally Posted by Gokhan
No, but the PCV oil mist (liquid-oil droplets) is responsible for most of the IVD. I can't post the whole Afton paper because of copyright issues, but I'll repeat its summary here. ---------------------------------------------------- Afton/SAE paper on IVD Formation of intake-valve deposits in gasoline direct-injection engines Gregory Guinther and Scott Smith -- Afton Chemical Corporation October 17, 2016 https:/
Originally Posted by circuitsmith
Are PCV fumes entirely responsible for IVDs?