The Positive Crankcase Ventilation (PCV) valve regulated crankcase pressure during various engine running conditions. At high vacuum (idle speed and partial load range) it will open slightly and at low vacuum (full throttle) it will open fully. This allows vapors to be drawn from the crankcase by engine vacuum and then sucked into the combustion chamber where they are burned.
REMOVAL & INSTALLATION
See Figures 1 and 2
The PCV valve must be replaced every 30,000 miles (48,300 km). Details on the PCV system, including system tests, are given in Driveability & Emissions Controls .
The valve is located in a rubber grommet on the valve cover, connected to the air cleaner housing by a large diameter rubber hose.
- Pull the valve (with the hose attached) from the rubber grommet in the valve cover.
- Remove the valve from the hose.
- Inspect the rubber grommet that houses the valve for deterioration, replace if needed.
- Install a new valve into the hose.
- Press the valve back into the rubber grommet in the valve cover.
Some vehicles are equipped with a PCV filter which is located in the air cleaner housing and must be replaced every 50,000 miles (80,000 km).
- Remove the air cleaner housing lid.
- Slide back the filter retaining clip and remove the old filter.
- Install the new filter, attach the retaining clip, then install the housing lid.