Visually inspect the PCV valve hose and the fresh air supply hose and their
attaching nipples or grommets for splits, cuts, damage, clogging, or restrictions.
Repair or replace, as necessary.
If the hoses pass inspection, remove the PCV valve from the rocker arm cover.
Shake the PCV valve and listen or feel for the rattle of the valve plunger
within the valve body. If the valve plunger does not rattle, the PCV valve
should be cleaned or replaced.
Fig. 1:Check the PCV valve for vacuum at idle
Start the engine and bring it to normal operating temperature.
Unplug the PCV valve and check for vacuum at the valve. If no vacuum is
felt check the hose for clogging.
Plug the valve back in. Remove the fresh air supply hose from the throttle
body air hose nipple, and plug or cap the nipple immediately to keep the engine
from stalling. Check for vacuum at the end of the supply hose using a stiff
piece of paper. If the paper is retained by vacuum at the end of the hose,
the PCV system is okay.
If the paper is not held by vacuum, check the fresh air and PCV hoses for
leaks or loose connections. Also check for a loose fitting oil fill cap or
loose dipstick. Correct as required until vacuum can be felt at the end of
the supply hose.
NOTE: If air pressure and oil or sludge is present at the
end of the fresh air supply hose, the engine has excessive blow-by and cylinder
bore or piston ring wear.
