Cooling System: Service and Repair: Overview
Cooling system components, removing and installing
Note:
^ As the engine warms up, cooling system pressure also increases. If necessary, release pressure before starting repair work.
^ Hoses are secured with spring clips. Only use spring clips when repairing.
^ VAG 1921 pliers are recommended for removing and installing spring clips.
^ When installing coolant hoses, route them stress-free, so they do not come into contact with other components (observe markings on coolant connections and hoses).
Perform cooling system leakage test with VAG 1274 cooling system tester adapters 1274/8 and 1274/9.
Cooling system components, body side
Cooling system components, engine side
Coolant hose connections, diagram
Engine coolant, draining and filling
Engine coolant, mixture ratios
Cooling system components, body side
1. Radiator
^ Removing and installing
^ After replacing change all engine coolant
2. O-ring
^ Always replace
3. Coolant hose, upper
^ Attached to radiator with clip
^ Check for proper fit.
^ Coolant hose connections
4. Connector
5. Retaining clip
^ Check for proper fit.
6. A/C Cutout Thermal Switch -F163
^ Before removing release pressure if necessary
7. From connector on cylinder head
^ Coolant hose connections
8. From connector on cylinder head/connector
^ Coolant hose connections
9. From ATF cooler
^ Only for vehicles with automatic transmission
^ Coolant hose connections
10. Electrical connector
^ Color: black
^ 2-pin connector
11. Cap
^ Check using VAG 1274 cooling system tester and VAG 1274/9 adaptor
^ Test pressure 1.4 to 1.6 bar
12. 10 Nm (7 ft. lbs.)
13. Coolant expansion tank
^ Check for cooling system leaks using VAG 1274 cooling system tester with VAG 1274/8 adapter
14. From connector to radiator for EGR/connector
^ Coolant hose connections
15. To cylinder head
^ Coolant hose connections
16. Fan shroud
17. Right coolant fan -V35-
^ checking
18. Fan bracket
^ Optional equipment
19. Retaining clip
^ Ensure it is seated securely
20. Coolant fan -V7
^ Checking
^ Ensure correct seating
21. Bracket
^ For radiator fan connector
22. Coolant hose, lower
^ Attached to radiator with clip
^ Coolant hose connection diagram
23. Electrical connector
^ Black, 3 pin connector
24. Coolant Fan Control (FC) Thermal Switch -F18-
^ Stage 1. ON: 92 to 97°C
^ Stage 1. OFF: 84 to 91°C
^ Stage 2. ON: 99 to 105°C
^ Stage 2. OFF: 91 to 98°C
25. Bracket
^ For radiator
^ Observe installation position
^ Comes in different versions
Cooling system components, engine side
1. Connector
2. Coolant hose, upper
^ Fastened to bulkhead
3. To heater core
^ Coolant hose connection diagram
4. From heater core
^ Coolant hose connection diagram
5. To connector in coolant hose, upper
^ Coolant hose connection diagram
6. Engine Coolant Temperature (ECT) Sensor -G62
^ Color: blue
^ For engine control module
^ with Engine Coolant Temperature (ECT) Sensor -G2-
^ Before removing release pressure if necessary
^ Checking:
7. Bracket
^ Check for firm fit
8. O-ring
^ Always replace
9. Connector
10. 10 Nm (7 ft. lbs.)
11. Coolant line
^ Coolant hose connection diagram
12. To radiator, upper part
^ Coolant hose connections, diagram
13. O-ring
^ Always replace
14. To expansion tank, lower part
^ Coolant hose connections, diagram
15. 15 Nm (11 ft. lbs.)
16. From radiator, lower part
^ Coolant hose connections, diagram
17. Coolant thermostat
^ Removing and installing
^ Checking: heat thermostat in water
^ Opening starts at approx. 85°C (185°F)
^ Ends approx. 105°C (221°F)
^ Opening lift: 7 mm min.
^ Check installation position.
18. Oil cooler
^ Removing and installing:
19. Coolant pump
^ Check for smooth movement
^ Replace when damaged or leaking
^ Removing and installing.
20. Cooler
^ For EGR
^ Removing and installing.
21. To expansion tank, upper
^ Coolant hose connections, diagram.