Mercedes of the S-class W202

1993-2000 of release

Repair and operation of the car



Mercedes W202
+ 1.2. General information
+ 2. Maintenance
+ 3. Engines
+ 4. Lubrication system
- 5. Cooling system
   + 5.2. Cooling liquid
   5.3. Antifreeze for a radiator
   5.4. Temperature regulator of cooling liquid (thermostat)
   5.5. Check of the cooling system
   5.6. Hydraulic coupling of the fan
   5.7. Pump of system of liquid cooling
   5.8. Radiator
   5.9. Fan casing
   5.10. Diagnostics of malfunctions of the cooling system
   5.11. Diagnostics of malfunctions of system of indication of level of liquid
   5.12. Engine overheat
+ 6. Heating, ventilation
+ 7. System of ignition
+ 8. Fuel system
+ 9. Transmission
+ 10. Running gear
+ 11. Steering
+ 12. Brake system
+ 13. Body
+ 14. Electric equipment
+ 14.2. Electrical circuitries






5. Cooling system

5.1. Contour of circulation of cooling liquid

GENERAL INFORMATION

As soon as the engine was cooled, cooling liquid circulates only in a head of the block of cylinders, and also in the block of cylinders of the engine and if the system of heating, in the heat exchanger is open. With increase in heating of the engine the regulator of cooling liquid (thermostat) opens a big circulating contour of cooling liquid. Cooling liquid goes through a radiator by means of the pump of system of liquid cooling which is constantly finding in operation. Cooling liquid proceeds through a radiator from top to down and at the same time is cooled by means of air which blows in cooling edges.

For regulation of air exchange in a radiator the krylchatka of the fan connected to the hydraulic coupling is connected. At shutdown of this coupling the fan rotates according to the frequency of rotation of a shaft of the engine, but not quicker than 1000 rpm. At a temperature of cooling liquid about 90 °C the bimetallic plate turns on the hydraulic coupling thanks to what according to the frequency of rotation of a shaft of the engine the frequency of rotation of the fan increases. If the frequency of rotation of the engine exceeds about 4500 rpm. (4000 rpm. at the diesel), the coupling fan because silicone oil in the coupling becomes too hot is automatically switched-off. As soon as the frequency of rotation of a shaft of the engine becomes lower than about 4500 rpm. (4000 rpm. at the diesel), the fan turns on again. Thanks to changeable operation of the fan the useful power of the engine increases and fuel consumption decreases.

Cooling system capacity at the 4-cylinder engine makes about 8,0 l, in the presence of the conditioner – about 9,0 l, and at the 6-cylinder engine about 10,0 l.

Cooling system capacity at the 2 l diesel engine about 8,0 l (about 9,0 l), at the 2,2 l engine about 7,0 l (about 7,5 l) and at the 2,5 l engine about 7,5 l. Values in brackets are valid for the vehicles equipped with the conditioner.