Table of contents: Technical data ↓ Tightening torques, Nm ↓
The cooling system is a closed liquid system, includes a water pump with an auxiliary belt drive from the crankshaft, a radiator fan with a thermoviscous clutch or an electric drive, a radiator, an expansion tank, a thermostat, a heater radiator, hoses and switches. When starting a cold engine, the coolant does not enter the radiator, since the thermostat valve is closed, but circulates through the cylinder block jacket and cylinder head, then enters the pump again. This ensures rapid warm-up of a cold engine. When the coolant reaches a certain temperature, the thermostat valve opens and the hot coolant passes through the hose to the radiator and is cooled by the oncoming air flow. The thermoviscous clutch of the radiator fan is activated depending on the air temperature behind the radiator. When a certain temperature is reached, the valve in the clutch opens and the fan impeller is activated.
Warnings: When opening the expansion tank cap on a hot engine, care must be taken as escaping vapors can cause severe burns. To do this, cover the expansion tank cap with a thick layer of cloth and slowly unscrew the cap until a hissing sound is heard. After the hissing stops, slowly unscrew and remove the cap from the expansion tank.
Avoid contact of coolant with clothing and body paintwork. If this happens, rinse the surface with plenty of water.
All clamps and clips that are damaged or cut during disassembly of the cooling system must be replaced with new ones during assembly. To fasten the band-type clamps, use special VAG 1921 pliers. All removable gaskets and sealing rings must be replaced with new ones. During assembly, the arrows on the cooling system elements, if any, must be aligned.
The drained coolant must be collected and disposed of.
Technical data
|
Thermostat
|
|
|
Temperature of opening start,°C
|
87
|
|
Full opening temperature,°C
|
102
|
|
Thermostat valve stroke, mm
|
8
|
Tightening torques, Nm
|
2.8L petrol engine
|
|
|
Thermostat housing mounting bolts
|
10
|
|
Coolant drain plug from the engine cylinder block
|
20
|
|
Water pump mounting bolts
|
10
|
|
Water pump pulley mounting bolt
|
25
|
|
Thermostat housing mounting bolts
|
10
|
|
Cooling system pipe fastening bolts to the cylinder block
|
10
|
|
Oil heat exchanger to radiator mounting bolts
|
10
|
|
Nuts for fastening the radiator to the front crossmember
|
20
|
|
Diesel engine 2.5 l
|
|
|
Coolant drain plug from the drain pipe
|
10
|
|
Water pump to cylinder block
|
10
|
|
Rear timing belt cover in cylinder head
|
10
|
|
Rear timing belt cover to fuel pump
|
10
|
|
Thermostat housing to cylinder block
|
10
|
|
Fuel pump drive pulley to camshaft
|
22
|
|
Plug for cylinder block
|
10
|
|
Front section of coolant pipe to cylinder block
|
22
|
|
Front section of coolant pipe to cylinder head
|
10
|
|
Rear timing belt cover to cylinder head
|
10
|
|
Rear timing belt cover to fuel pump
|
10
|
|
Diesel engine 3.3 l
|
|
|
Water pump to cylinder block
|
10
|
|
Rear timing belt cover to cylinder head
|
10
|
|
Timing Belt Guide Roller
|
70
|
|
Thermostat housing
|
10
|
|
Middle pipe of the cooling system to the cylinder head
|
10
|