The system consists of an oil separator located under valve cover valve cover gasket number 103 016 04 21 for replacment, distribution tube on intake manifold, and return flow tube. California models are equipped with a diaphragm regulating valve located in the oil separator.

When the engine is running, blow-by gases flow through the oil separator, and to the distribution tube on the intake manifold, through a connecting hose. Oil from the separator returns to the cylinder head through the return flow tube.

On Mercedes Bens California models, the diaphragm regulating valve is used to prevent excessive vacuum from forming in crankcase.

The system consists of an oil separator located in the valve cover, idle speed air distributor 000 141 22 25, 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 000 141 22 25, 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. Make sure you always check your engine maintanance guide.

Fig. 2: Crankcase Ventilation System (190E 2.3) 190E 2.3-16

The system consists of an oil separator located in the valve cover, idle speed air distributor,coolant lines and connecting hoses, idle speed air line.

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.If needed replace the air filter number 003 094 54 04.

To ensure against vent line freezing, coolant is routed to vent line from cylinder head. Coolant returns to water pump through coolant return line..

The system consists of a fresh air hose from air cleaner to right cylinder head cover, a breather hose from left cylinder head cover hose number 103 094 10 82, an orifice, and a connection to intake system.

During idle or low speed operation, vapors are drawn through the orifice, into the idle air distribution tubes, then into the intake manifold. Fresh air to vent the engine comes through the air cleaner and right cylinder head cover hose. During high speed operation the vapors are drawn in through the air cleaner and burned.

The crankcase ventilation system is maintenance free, but hoses should be checked to ensure that they are not cracked and are free of obstructions.

.