Cooling System
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.
• Cover the coolant reservoir cap with a cloth and then open it slowly to release the pressure.
Danger of personal injury due to the coolant fan turning on by itself.
• Disconnect the connectors before working near the fan shroud.
• Secure all hose connections with hose clamps of the same type as those equipped by the factory, refer to the Parts Catalog.
• The arrows on the coolant pipes and ends of coolant hoses must align.
• Blue = large coolant circuit.
• Red = small coolant circuit.
• Orange = coolant circuit for the charge air cooler.
• Brown = heating circuit.
• The arrows show the coolant flow direction.
Vehicles without Auxiliary Heater
1 Front Charge Air Cooling Circuit Radiator
• Change coolant after replacing
2 Radiator
• Vehicles with dual clutch transmission: With integrated ATF cooler
• Change coolant after replacing
3 Coolant Temperature Sensor (G62)
4 Coolant Thermostat
5 Coolant pump
6 Charge Air Cooler on the Right Side
• inside the compressor housing
• change coolant after replacing
7 Coolant Switch-Off Valve
• is controlled by the auxiliary heater exhaust gas sensor (N422)
• The auxiliary heater exhaust gas sensor (N422) is controlled by the Climatronic control module (J255).
8 Bleeder Screw
9 Cylinder Head Bank 1 (right)
• change coolant after replacing
10 Heat Exchanger for Heater Unit
• change coolant after replacing
11 Bleeder Hole
12 Cylinder Head Bank 2 (left)
• change coolant after replacing
13 Bleeder Screw
14 Left Charge Air Cooler
• Inside the compressor housing
• Change coolant after replacing
15 Coolant Reservoir Cap
• Pressure relief valve, checking => [ Pressure Relief Valve in Cap, Checking ] Testing and Inspection
16 Coolant Reservoir
17 Engine Oil Cooler
18 After-Run Coolant Pump (V51)
• Depending on country
19 Non-Return Valve
• In the coolant hose
20 Charge Air Coolant Pump (V188)
21 Left Charge Air Cooling Circuit Radiator
• change coolant after replacing
22 Non-Return Valve
• In the coolant hose
23 Non-Return Valve
• In the coolant hose