Some 2011 Audi Q7 vehicles may experience insufficient cabin heat after periods of engine idling. The complaint may reoccur after bleeding the cooling system.
Because of an incorrect ventilation hose to the coolant reservoir, or an incorrect non-return valve in the ventilation hose, air moves from the reservoir into the coolant circuit.
Replace hose #41 as shown in the accompanying illustration. The check valve in the hose should be positioned at the lower connection, behind the transmission. Confirm this location before installing the hose. The check valve should be approximately 70mm from the end of the hose. The position can be checked by gently squeezing the hose with your fingers.
- Drain coolant per the repair manual, collecting it into a clean container for reuse.
- Replace the ventilation hose with the non-return valve and confirm proper position of the check valve.
- Perform a complete drain and refill as outlined in the repair manual. The bleeding procedure must be followed completely to ensure that the cooling system is properly bled.