A/C - Insufficient Heat Output At Idle
19 - Q7 3.0I TFSI, heating performance too low19 11 27
2026377/2
December 6, 2011.
Supersedes Technical Service Bulletin Group 19 number 11 - 24 dated May 19, 2011 for reasons listed below.
Affected Vehicles
Condition
Insufficient heating performance at idle speed with engine at operating temperature.
The passenger compartment is not warm enough after periods of engine idling. The complaint may reoccur after bleeding the cooling system.
Technical Background
Because of an incorrect ventilation hose to the coolant reservoir, or an incorrect non-return valve in the ventilation hose, (Figure 1, 21) air moves from the reservoir into the coolant circuit.
Replace hose (Figure 2, 41). The check valve in the hose should be positioned at the lower connection, behind the transmission. Confirm location before installing the hose. The check valve should be approximately 70 mm from the end of the hose; the position can be checked by gently squeezing the hose with fingers.
Production Solution
Optimized ventilation hose with non-return valve from February 2011 production.
Service
1. Drain coolant per repair manual, collect coolant into clean container for reuse.
2. Replace the ventilation hose with non-return valve; confirm proper position of check valve.
3. Perform complete drain and filling as out lined in repair manual, the bleeding procedure must be followed completely to ensure the cooling system is bleed properly. 19 Cooling System> General Information> Cooling System, draining and filing.
Warranty
Required Parts and Tools
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service manuals for the latest information.