Chrysler Caravan/Voyager/Town n Country 1984-1995

PCV Valve

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See Figures 1, 2, 3 and 4



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Fig. Fig. 1: Removing the PCV valve from the crankcase vent module



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Fig. Fig. 2: PCV valve-2.5L engines



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Fig. Fig. 3: PCV valve-3.0L engines



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Fig. Fig. 4: PCV valve-3.3L and 3.8L engines

OPERATION



Except 2.6L Engines

Crankcase vapors and piston blow-by are removed from the engine by intake manifold vacuum. The emissions are drawn through the PCV valve (usually located in the top of the engine valve cover) into the intake manifold where they become part of the air/fuel mixture. Crankcase vapors are then burned and pass through the exhaust system. When there are not enough vapors or blow-by pressure in the engine, air is drawn from the air cleaner. With this system no outside air enters the crankcase.

The PCV valve is used to control the rate at which crankcase vapors are returned to the intake manifold. The action of the valve plunger is controlled by intake manifold vacuum and the spring. During deceleration and idle, when manifold vacuum is high, it overcomes the tension of the valve spring and the plunger bottoms in the manifold end of the valve housing. Because of the valve construction, it reduces, but does not stop, the passage of vapors to the intake manifold. When the engine is lightly accelerated or operated at constant speed, spring tension matches intake manifold vacuum pull and the plunger takes a mid-position in the valve body, allowing more vapors to flow into the manifold.

2.6L Engines

Intake manifold vacuum draws air from the air cleaner through the valve cover into the engine, the outside air is mixed with crankcase vapors and piston blow-by and drawn through the PCV valve (located in the top end of the engine cover) and into the intake manifold where it becomes part of the air/fuel mixture. The vapors are burned and expelled with exhaust gases.

TESTING



See Figures 5 and 6



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Fig. Fig. 5: Checking for vacuum at the PCV valve



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Fig. Fig. 6: A good PCV valve will rattle when shaken

  1. Place the vehicle in Park, or Neutral (if equipped with a manual transaxle). Set the parking brake and block the wheels.
  2.  
  3. Start the engine and allow to idle until normal operating temperature is reached.
  4.  
  5. With the engine idling, remove the PCV valve, with hose attached, from its rubber molded connector.
  6.  
  7. When the PCV valve is free of its mounting, a hissing noise will be heard and a strong vacuum felt when a finger is placed over the valve inlet. When the engine is turned OFF , the valve should rattle when shaken. If the valve is not operating properly it must be replaced.
  8.  

REMOVAL & INSTALLATION



  1. With the engine OFF , clean PCV valve area with a suitable solvent.
  2.  
  3. Remove the PCV valve from the mounting grommet on the top cover (2.6L, 2.5L, 3.0L, 3.3L and 3.8L engines) or from the vent module (2.2L engines). Disconnect the hose from the valve.
  4.  
  5. Examine the vacuum hose and replace if the hose is cracked, broken or dried out. Always check the vent hose for clogging. If clogged, replace or clean as necessary.
  6.  
  7. Install a new PCV valve into the hose and install into mounting grommet.
  8.  

 
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