Mazda MX-3 silhouetteMX-3

POSITIVE CRANKCASE VENTILATION (PCV) SYSTEM

F2-124prose procedure

DESCRIPTION

The PCV valve is operated by the intake manifold vacuum.
When the engine is running at idle, the PCV valve is slightly open and a small amount of blowby gas is drawn into the dynamic chamber to be burned.
As the engine speed rises, the PCV valve is opened further, allowing a larger amount of blowby gas to be drawn into the dynamic chamber.

PCV VALVE

Inspection

  1. 1
    Start the engine and let it idle.
  2. 2
    Disconnect the PCV valve together with the ventilation hose from the cylinder head cover.
    Close-up illustration of a hand disconnecting/holding the PCV valve and ventilation hose at the cylinder head cover in the engine bay. Labelled PCV VALVE.
  3. 3
    Block the PCV valve opening.
  4. 4
    Verify that vacuum is felt.
  5. 5
    Remove the PCV valve.
  6. 6
    Blow through the valve from port A and verify that air comes out from port B.
    Detail drawing of the PCV valve itself (elbow-shaped valve) with its two ports identified by callout balloons: port B at the lower/left opening and port A at the right opening.
  7. 7
    Blow through the valve from port B and verify that no air comes out from port A.
  8. 8
    Replace the PCV valve if not as specified.
Support our work!

Search Manual

Search pages, specs, and procedures