Positive Crankcase Ventilation System

During normal compression stroke, a small amount of gases in the combustion chamber escapes past the piston. Approximately 70% of these "blowby" gases are unburned fuel (HC) that can dilute and contaminate the engine oil, cause corrosion to critical parts, and contribute to sludge build up. At higher engine speeds, blowby gases increase crankcase pressure that can cause oil leakage from sealed engine surfaces.

The purpose of the Positive Crankcase Ventilation (PCV) system is to remove these harmful gases from the crankcase before damage occurs and combine them with the engine's normal incoming air/fuel charge. Fuel injected Toyota vehicles use two different types of closed PCV systems to prevent the escape of crankcase vapors into the atmosphere:

• Fixed Orifice PCV System

• PCV System Using Variable Flow PCV Valve

• PCV System Using Variable Flow PCV Valve

Pcv System Diagram

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Responses

  • TUOMAS
    How does a fuel injected car start diagram?
    7 years ago
  • tekle
    How does toyota supra crankcase ventilation system work?
    3 years ago
  • Bucca
    Does hillux vigo champ use positive crankcase valve?
    1 year ago
  • Barbara
    How does an Engine positive crankcase ventilation work in a 1KZ?
    1 year ago

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