Removing and installing heater coolant shut-off valve - vehicles with TDI engine — AUDI

🧭 Before you start

Switch off ignition and heater, drain the coolant and move the fuel filter aside with lines attached. Mark the hoses, detach them, unplug the connector, undo the nuts and remove the valve, then separate it from its bracket. Refit with the hoses in their marked positions and standard clips, bleed the cooling circuit and check N279 operation.

Fits: Audi Q7 (4M, 2015–)

• Opens: coolant
• Also covered elsewhere: Electronic parts catalogue

Don't miss

• Drain the coolant; there is no room to clamp the hoses on this engine.
• Mark each coolant hose's position on the valve before removal.
• Interchanged hoses cause the passenger compartment heating to fail.
• Counterhold the nuts when removing the bracket bolts.
• Bleed the cooling circuit and check N279 activation after fitting.

Written for this job from the workshop steps below · TorqFix editorial.

📋 Procedure

1. Switch off ignition (and auxiliary/supplementary heater).
2. Drain cooling system 19Cooling system/coolant; Draining and filling cooling system. [Note: The coolant must be drained as there is not sufficient space in this engine to clamp off the coolant hoses in the vicinity of the shut-off valve. On vehicle versions where there is enough space to clamp off the coolant hoses, there is no need to drain the coolant Removing and installing heater coolant shut-off valve - vehicles with petrol engine.]
3. Remove fuel filter together with bracket and move them to one side with lines connected Fuel supply system20Fuel filter; Removing and installing fuel filter.
4. Mark arrangement of coolant hoses at shut-off valve.
5. Loosen hose clips and detach coolant hoses (1, 2, 6).

6. Unplug electrical connector (7).
7. Unscrew nuts (4 and 5).
8. Remove shut-off valve (3).
9. Remove bolts (1) (counterhold nuts (2)).
10. Detach shut-off valve (3) from bracket (4).
11. ⚠ Ensure correct assignment of coolant hoses at shut-off valve. If coolant hoses are interchanged, this can cause the heating in the passenger compartment to fail. — Butt-joint coolant hoses and secure with standard hose clips at marked locations. For correct version of hose clip refer to Electronic parts catalogue.
12. Bleed coolant circuit .
13. If applicable, check activation and operation of heater coolant shut-off valve N279 ("“Guided Fault Finding”").

Other AUDI procedures

• Removing and installing toothed belt – Audi · 56 torque figures
• Removing engine – Audi A8 D3 · 41 torque figures
• Removing camshaft timing chain from camshafts – Audi A6/A7 C7 · 38 torque figures
• Installing engine – Audi A8 D4 · 36 torque figures
• Removing and installing camshaft timing chain · 29 torque figures
• Checking actuation of electric additional heater by engine control unit
• Performing zero compensation of brake pressure sender 1 G201 and brake pressure sender 2 G214
• Dismantling and assembling auxiliary heater (version “1”, horizontal installation)
• Dismantling and assembling auxiliary heater (version “2”, vertical installation)
• Poly V-belt drive for power steering pump, alternator and air conditioner - exploded view of components