POSITIVE CRANKCASE VENTILATION (PCV) SYSTEM [SKYACTIV-X 2.0]

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Positive Crankcase Ventilation (PCV) System

Purpose, outline

•  Prevents release of blow-by gas (unburnt gas) into the atmosphere.

•  The intake manifold vacuum introduces blow-by gas to the intake manifold via the PCV valve and PCV hose.

•  Fresh air is introduced to the crank case to suppress engine oil deterioration.

•  Fresh air flows to the crank case via the ventilation hose according to the crank case vacuum.

System diagram

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Structure

•  The positive crankcase ventilation system consists of the following parts:

Part name	Reference
PCV valve	(See Positive Crankcase Ventilation (PCV) Valve.)
PCV hose	―
Ventilation hose	―
Check valve	(See Check Valve.)

Positive Crankcase Ventilation (PCV) Valve

Purpose, function

•  The PCV valve adjusts the reflux amount by the intake manifold vacuum.

Construction

•  The PCV valve is installed to the cylinder head cover.

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•  The PCV valve consists of a body, spring and valve.

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Operation

•  When the valve is pulled by the intake manifold vacuum, blow-by gas flows to the intake manifold.

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•  Blow-by gas flow amount is adjusted by the spring according to the intake manifold vacuum.

Check Valve

Purpose, function

•  The check valve prevents flow back of intake air from the supercharger to the cylinder head cover.

Construction

•  The check valve is installed to the cylinder head cover.

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•  The check valve consists of the body, top cover, under cover, and seal.

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Operation

•  The check valve is opened to protect the supercharger parts while the supercharger is not operating.

•  The check valve is closed to prevent flow back of intake air from the supercharger into the cylinder head cover while the supercharger is operating.

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