Work sequence

WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, and 2003 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Removing Engine Cover

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Remove engine cover - arrows -.

Fig 2: Vacuum Hose Disconnected At Combination Valve

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Disconnect vacuum hose - arrow - at combination valve.
Connect vacuum hand pump VAG1390 to vacuum hose of combination valve.

Fig 3: Noise Insulation Tray Retainers

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Remove sound insulation - arrows -.

Fig 4: Disconnecting Hose At Line For Secondary Air Combination Valve

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Disconnect hose - arrow - at line for secondary air combination valve.
Connect test hose to line...
.. and blow into hose with slight pressure (do not use compressed air).

Combination valve should be closed. It should not be possible to blow through hose.

Operate vacuum hand pump.

Combination valve should open. It should now be possible to blow through hose.

If combination valve does not open:

Replace combination valve → Secondary air combination valve, removing and installing .