The UK quattro Network
The UK's mobile Audi 5-cylinder mechanic - 07833 654800, 24x7
Specialist in turbos, quattros, electrics and non-starts

WR Auxiliary Air Valve - Part # 035 133 453 A/C/E

The auxiliary air regulator allows more air/fuel mixture when the engine is cold in order to improve driveability and provide idle stabilization. The increased air volume is measured by the air flow sensor and fuel is metered accordingly. The auxiliary air valve contains a specially shaped plate attached to a bi-metal spring. The plate changes position according to engine temperature, allowing the most air to pass when the engine is cold. As temperature rises, the bi-metal spring slowly closes the air passage and the valve should close completely when the engine is at operating temperature. The bi-metal spring is also heated electrically, allowing the opening time to be limited according to engine type.

Testing

Note: The engine must be cold to start this test

• Disconnect the electrical terminal plug and the two air hoses at the auxiliary air valve.
• Voltage must be present at the terminal plug with the ignition switch ON.
• Check the continuity of the heater coil by connecting a test light or Ohmmeter to the terminals on the valve.
• Use a mirror to look through the bore of the valve. If the air valve is not open, replace the auxiliary air valve.
• Connect the terminal plug and the two air hoses to the auxiliary air valve.
• Start the engine: the auxiliary air valve bore should close within 5 minutes of operation by cut-off valve.
• The valve should be closed when the engine is hot. If it is still open, starting problems may result and the auxiliary air valve should be replaced.

Quick test: Pinching the upper hose together completely should affect idle when the engine is cold but not when it is hot.

Kerbside Motors Home Page and Contact Information

Contact Phil Payne by email or use mobile/SMS 07833 654800