Crankcase Emission Control System - 2.0L: Overview Kia Optima III

Scheme 4

Scheme 5

1. After disconnecting the vapor hose from the PCV valve, remove the PCV valve. Visually check for a collapsed vapor hose or hose leaks.
2. Reconnect the PCV valve to the vapor hose.
3. Run the engine at idle, then put a finger over the open end of the PCV valve and make sure that intake manifold vacuum can be felt. NOTE: The plunger inside the PCV valve will move back and forth at vacuum.
4. If the vacuum is not felt inspect PCV operation, if operating correctly clean or replace the vapor hose.

Operation Principle

OPERATION PRINCIPLE OF POSITIVE CRANKCASE VENTILATION (PCV) VALVE Engine Condition Not Running Idling or Decelerating Normal Operation Accelerating and High Load Vacuum in intake Manifold 0 High Moderate Low PCV Valve Close Slightly Open Properly Open Fully Open Blow-by Gas Flow 0 Small Medium Large Schematic Diagram Intake Manifold Intake Manifold Intake Manifold Intake Manifold

Scheme 6

Scheme 7

Scheme 8

Scheme 9

1. Disconnect the vapor hose (A).
2. Remove the PCV valve (B).

Scheme 10

1. Insert a thin stick (A) into the PCV valve (B) from the threaded side to check that there is the plunger movement.

Note. If the plunger does not move (PCV valve is clogged), clean or replace the valve.