A6 Quattro Sedan V8-4.2L (BVJ) (2007)
Heater Core: Service and Repair
Preparation For Heater Core Removal
Preparation For Heater Core Removal
NOTE: With ignition on, valves of pump valve unit ( Left Heat Regulating Valve N175 and Right Heat Regulating Valve N176 ) are constantly
actuated as a function of temperature setting on control and display unit, Climatronic Control Module J255. Valves may therefore be warm or even hot
despite engine being cold.
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Switch off ignition.
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Dissipate pressure in coolant circuit by opening cap at coolant expansion tank Relevant engine, mechanics.
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Remove plenum chamber cover.
CAUTION: The two valves of the pump valve unit may be hot even if the engine is cold.
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Remove wiper arms and scuttle panel trim.
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Remove dome brace if necessary (not installed on all vehicles).
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Pinch off coolant hose - A - (return from heater core to engine), e.g. using Hose Clamps Up To 25 mm Dia. 3094.
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Mark arrangement of coolant hoses - A - (supply to left heater core) and - B - (supply to right heater core).
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Unplug connector - D - (to Left Heat Regulating Valve N175 and Right Heat Regulating Valve N176 ).
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Unplug connector - E - (to Coolant Pump V50 ).
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Pinch off coolant hose - C - (supply from engine to Coolant Pump V50 ) e.g. using Hose Clamps Up To 25 mm Dia. 3094.
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Disconnect coolant hoses - A - and - B - from connections of pump valve unit.