Mechanical Diagrams
Coolant Hose Connection Diagram
Risk of scalding due to hot steam and hot coolant.
• The coolant system is under pressure when the engine is warm.
• Reduce pressure by covering coolant reservoir cap with a cloth and carefully opening.
• When the engine is warm the cooling system is under pressure. If necessary release pressure before commencing repair work.
• Secure all hose connections using hose clamps appropriate for the model type. Refer to the Parts Catalog.
• The hose clip pliers (V.A.G 1921) or hose clip pliers (VAS 6340) are recommended for installing spring clamps.
• Always replace gaskets and seals.
• Arrows on coolant pipes and coolant hoses must line up across from each other.
• Blue = large coolant circuit.
• Red = small coolant circuit.
• Brown = heating circuit.
1 Radiator
• Change coolant after replacing
2 Turbocharger
3 Cylinder Head/Cylinder Block
• Change coolant after replacing
4 Coolant Switch-Off Valve
• Controlled by a vacuum from the Climatronic refrigerant shut-off valve (N422)
• Removing and installing,
5 Bleeder Hole
6 Heat Exchanger for Heater Unit
• Change coolant after replacing
7 Coolant Pump (V50)
• Installed only on vehicles with a start/stop system
8 Coolant Pump
• Removing and installing, refer to => [ Coolant Pump ] Coolant Pump
9 Restrictor
10 Coolant Reservoir Cap
• Pressure relief valve, checking => [ Pressure Relief Valve In Cap, Checking ] Testing and Inspection
11 Coolant Reservoir
12 Check Valve
13 After-Run Coolant Pump (V51)
• Installed only on hot climate vehicles
14 Coolant Thermostat
15 Engine Coolant Temperature (ECT) Sensor (G62)
• Removing and installing, refer to => [ Engine Coolant Temperature Sensor (G62) ] Service and Repair
16 Engine Oil Cooler