Genuine Toyota Avalon PCV Valve

Toyota Avalon PCV Valve Parts Questions & Answers

• Valve Sub-Assy, Ventilation
  12204-31040
  Q: What is the Role and Importance of the Positive Crankcase Ventilation (PCV) System and PCV Valve in Reducing Hydrocarbon Emissions?

  A: The Positive Crankcase Ventilation (PCV) system reduces hydrocarbon emissions by scavenging crankcase vapors. It circulates fresh air from the air cleaner through the crankcase, mixing it with blow-by gases. The mixture is rerouted through a PCV valve to the intake manifold. The PCV valve restricts flow when intake manifold vacuum is high, maintaining idle quality. In abnormal conditions, excessive blow-by gases flow back through the crankcase vent tube into the air cleaner for normal combustion. The PCV system consists of the PCV valve, blow-by filter, and vacuum hoses connecting these components to the engine. Regularly checking and replacing the PCV valve is important.
• Valve Sub-Assy, Ventilation
  12204-20010
  Q: What is the Positive Crankcase Ventilation (PCV) system and PCV Valve and how does it work to reduce hydrocarbon emissions on Toyota Avalon and Toyota Solara?

  A: The Positive Crankcase Ventilation (PCV) system reduces hydrocarbon emissions by cutting crankcase vapors. It does this by circulating fresh air from the cleaner to the crankcase, mixing it with blow-by gases. These gases are moved through a PCV valve and taken back to the intake. The PCV has the PCV valve, a blow-by filter, and vacuum hoses connecting them to the engine. The PCV valve is intended to block flow during high-intake vacuum conditions to maintain consistent quality. If there is anything unusual, the system allows blow-by gases to go back into the air cleaner from the vent tube.
• Valve Sub-Assy, Ventilation
  12204-20040
  Q: How Do You Check and Replace the PCV Valve and Hose on Toyota Avalon and Toyota Solara?

  A: The PCV valve and hose are in the valve cover. Disconnect the hose and remove the valve for testing. Test for vacuum at the valve opening while the engine idles. If there's no vacuum, check for a blocked hose or valve and replace if necessary. Blow through the PCV valve from the cylinder head end. If air doesn't pass, replace the valve. Ensure a new valve matches your vehicle and engine size.
• Valve Sub-Assy, Ventilation
  12204-20020
  Q: Where is the PCV valve and hose located and how do you check it?

  A: The PCV valve and hose is located in the valve cover. To check it, disconnect the hose and pull the PCV valve from the cover, then reconnect the hose. With the engine idling at normal operating temperature, place your finger over the valve opening. If there's no vacuum at the valve, check for a plugged hose or valve and replace any plugged or deteriorated hoses. After this, turn off the engine and remove the PCV valve from the hose. Blow through the valve from the valve cover (cylinder head) end. If air will not pass through the valve in this direction, replace it with a new one. To check the PCV valve, first attach a clean section of hose to the cylinder head side of the valve and blow through it - air should pass through easily - then blow through the opposite side of the valve and verify that air doesn't pass through it. When purchasing a replacement PCV valve, make sure it's for your particular vehicle and engine size. Compare the old valve with the new one to make sure they're the same.