Ford Full-Size Cars 1968-1988 Repair Guide

PCV Valve


See Figures 1 and 2

Most models use a closed ventilation system with a sealed breather cap connected to the air cleaner by way of a rubber hose. The PCV valve is usually mounted in the valve cover and connected to the intake manifold by a rubber hose. The PCV valves main task is to regulate the amount of crankcase (blow-by) gases which are recycled.

Since the PCV valve works under severe load, it is important that it be replaced at the interval specified in the Maintenance Interval Chart. Replacement involves removing the valve from the grommet in the rocker arm cover, then disconnecting the hose(s) and installing a new valve.

If The PCV hose becomes brittle or clogged replace the PCV hose at this time.

Click image to see an enlarged view

Fig. Fig. 1: PCV system used on early models

Click image to see an enlarged view

Fig. Fig. 2: Exploded view of a PCV system used on later models


See Figure 3

  1. Remove the PCV valve from the grommet or elbow, by twisting back and forth, then pulling it out.
  3. Disconnect the hose(s) from the PCV valve and remove the valve from the vehicle.

Click image to see an enlarged view

Fig. Fig. 3: Twist the PCV valve back and forth and pull it from the grommet

  1. Check the PCV valve for deposits and clogging. If the valve rattles when shaken, most likely it is okay. If the valve does not rattle, clean the valve with solvent until the plunger is free, or replace it.
  3. Check the PCV hose(s) and the grommet for clogging and signs of wear or deterioration. Clean or replace parts, as necessary.

To install:
  1. If removed, install a new grommet.
  3. Connect the PCV hose(s) to the PCV valve.
  5. Install the PCV valve in the grommet or elbow.