GM Camaro 1982-1992 Repair Guide

Crankcase Ventilation System

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See Figures 1 through 6

OPERATION



The Positive Crankcase Ventilation (PCV) system is used to control crankcase blow-by vapors. As the engine is running, clean, filtered air is drawn through the air filter and into the crankcase. As the air passes through the crankcase, it picks up the combustion gases and carries them out of the crankcase, through the PCV valve, and into the induction system. As they enter the intake manifold, they are drawn into the combustion chamber where they are reburned.

The most critical component in the system is the PCV valve. This valve controls the amount of gases which are recycled into the combustion chamber. At low engine speeds, the valve is partially closed, limiting the flow of gases into the intake manifold. As engine speed increases, the valve opens to admit greater quantities of gases into the intake manifold. If the PCV valve becomes clogged, the system is designed to allow excessive amounts of blow-by gases to back flow through the crankcase tube into the air cleaner to be consumed by normal combustion.



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Fig. Fig. 1: PCV flow on 4, 6 and 8cylinder engines

SERVICE



Inspect the PCV system hose and connections at each tune-up and replace any deteriorated hoses. Check the PCV valve at every tune-up and replace it at 30,000 mile intervals.

TESTING



  1. Remove the PCV valve from the intake manifold or valve cover.
  2.  
  3. Run the engine at idle.
  4.  
  5. Place your thumb over the end of the valve. Check for vacuum. If there is no vacuum at the valve, check for plugged valve or vacuum lines.
  6.  



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Fig. Fig. 2: Check the PCV valve for vacuum at idle

  1. Shut off the engine. Shake the valve and listen for the rattle. If valve doesn't rattle, replace it.
  2.  

REMOVAL & INSTALLATION



PCV System Filter
  1. To replace the PCV filter disconnect the hose, if equipped, attached to the filter at the air cleaner and remove the air cleaner cover. Slide the spring clamp off of the filter and remove it from the air cleaner.
  2.  
  3. Inspect the rubber grommet in the valve cover and the hose for signs of deterioration, brittleness and cracking. Replace as necessary.
  4.  
  5. Installation is the reverse of removal.
  6.  

PCV Valve
  1. Disconnect the hose or pipe from the PCV valve.
  2.  
  3. Gently pull the PCV valve out of the grommet in the valve cover or intake manifold.
  4.  
  5. Installation is the reverse of removal.
  6.  



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Fig. Fig. 3: PCV system on Tuned Port Injection equipped engines



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Fig. Fig. 4: PCV filter location on most carbureted and throttle body injected engines



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Fig. Fig. 5: Most PCV valves are located in the rocker arm covers



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Fig. Fig. 6: Once the valve has been withdrawn from the rocker cover, it can be removed from the hose and replaced

 
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