Description & Operation
All engines are equipped with the Positive Crankcase Ventilation (PCV) system. The PCV system vents crankcase gases into the engine air intake where they are burned with the fuel and air mixture. The PCV system keeps pollutants from being released into the atmosphere. It also helps to keep the engine oil clean, by ridding the crankcase of moisture and corrosive fumes. The PCV system consists of the PCV valve, the nipple in the air intake and the connecting hoses.
Incorrect operation of the PCV system can cause multiple driveability symptoms.
A plugged valve or hose may cause:
A leaking valve or hose would cause:
Diagnosis & Testing
- Disconnect the ventilation hose from the PCV valve. Remove the PCV valve from the engine. Once removed, reconnect the ventilation hose to the valve.
- Start the engine and allow to idle. Place a finger over open end of the PCV valve. Make sure intake manifold vacuum is felt on finger.
- If vacuum is not felt, the PCV valve may be restricted.
- Turn the engine OFF and remove the PCV valve from the hose.
- Insert a thin stick into the threaded end of the PCV valve. Push on the inner plunger and inspect for movement.
- If plunger inside the PCV valve is not free to move back and forth, the valve is clogged and will require replacement.
Removal & Installation
- Disconnect the negative battery cable.
- If necessary for access, remove the air intake hose and air cleaner assembly.
- If necessary, unfasten the retaining clamp, then disconnect the ventilation hose from the PCV valve.
- Remove the PCV valve from the camshaft (rocker) cover.
- Install the PCV valve into the rocker cover. If the valve is threaded, tighten the valve until snug.
- Reconnect the ventilation hose to the valve.
- If removed, install the air intake hose and the air cleaner assembly.
- Connect the negative battery cable.