Engine codes AEG, AVH and AZG (from model year 1999)

Fig 1: Exploded View Of Cooling System (Engine Codes AEG, AVH & AZG From Model Year 1999)

Courtesy of VOLKSWAGEN UNITED STATES, INC.

1 - To top of expansion tank 

2 - O-ring 

• Replace if damaged

3 - Connection heater heat exchanger 

4 - Connector 

• 4-pin
• Wiring chamber 3 and wiring chamber 4 for Engine Coolant Temperature (ECT) sensor -G62-
• Gold plated contacts for ECT -G62-

5 - Engine Coolant Temperature (ECT) sensor -G62- 

• For engine control module
• With Engine Coolant Temperature (ECT) Sensor -G2-
• Gold plated contacts for Engine Coolant Temperature (ECT) Sensor -G62-
• Release pressure in coolant system if necessary, before removing components

6 - Retaining clip 

• Check seated securely

7 - From heat exchanger 

• Coolant hose connection diagram, AEG engine. Refer to Engine code AEG 
• Coolant hose connection diagram for engines AVH and AZG. Refer to Engine codes AVH, AZG, BBW, BEV 

8 - Coolant pipe 

9 - From ATF radiator (automatic transmission) or shape hose 

10 - 10 Nm 

11 - To bottom of expansion tank 

12 - O-ring 

• Always replace

13 - Union 

14 - To top of radiator 

15 - From bottom of radiator 

16 - Oil cooler 

• Ensure clearance to adjacent components
• Note. Refer to Lubrication system components, removing and installing 

17 - 15 Nm 

18 - Coolant thermostat 

• Checking: Heat up thermostat in water
• Starts to open at approx. 86 ° C
• Opening stroke: min. 7 mm
• Removing and installing. Refer to Thermostat, removing and installing 

19 - Toothed belt 

• Mark direction of rotation before removing
• Check for wear
• Do not kink
• Removing, installing and tensioning. Refer to Engine codes AEG, AVH, AZG, BEV 

20 - Coolant pump 

• Check for ease of movement
• If damaged or leaking replace complete
• Removing and installing. Refer to Coolant pump, removing and installing 

21 - Rear toothed belt guard 

22 - 20 Nm 

23 - Throttle valve control module 

• Heated by coolant