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Home >> Ford >> 1991 >> Bronco 4.9 Y, Standard, M5OD-R2 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Emission Systems & Sub-Systems >> Positive Crankcase Ventilation (PCV) >> PCV Valve
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PCV Valve

  1. Remove PCV valve from rocker cover grommet. Shake valve. Valve should rattle when shaken. If valve does not rattle, replace valve.
  2. Start engine and warm to normal operating temperature. On 2.3L, 2.9L and 4.9L engines, remove corrugated hose from oil separator nipple. Place stiff piece of paper over nipple end and wait 60 seconds.
  3. On all other engines, disconnect hose from remote air cleaner or outlet tube. Place stiff piece of paper over hose end and wait 60 seconds. Vacuum should hold paper in place. If vacuum does not hold paper in place, replace valve.
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