Gasoline Models: 190E
The system consists of an oil separator located in the valve cover, idle speed air distributor, and a connecting hose.
When the engine is operating under high intake manifold vacuum, blow-by gases flow out of the valve cover, through the by-pass bore in the idle speed air distributor, and into the intake manifold idle speed air passage. A small amount of filtered air is drawn into system through the by-pass hole.
When the engine is operating at low or no intake manifold vacuum, blow-by gases flow into the air cleaner where they are mixed with filtered air before burning.