Mercedes-Benz G-class (W463) since 1999 of release
1. Introduction
2. Governing bodies and operation receptions
3. Current leaving and service
4. Engine
5. Systems of cooling, heating, ventilation and air conditioning
5.1. System of cooling of the engine
5.1.1. Antifreeze - means of protection from freezing
5.1.2. Replacement of cooling liquid - general comments
5.1.3. Check of a cover of system of cooling, replacement of hoses of system of cooling
5.1.4. Thermostat check
5.1.5. Removal and thermostat installation
5.1.6. Removal and installation of a radiator of system of cooling
5.1.7. Removal and installation of a broad tank
5.1.8. Removal and installation of assembly of the fan of system of cooling
5.1.9. Removal and installation of the water pump
5.1.10. Removal and installation of a low-temperature cooler (М612)
5.1.11. Removal and installation of a heater of the block of the engine (at the corresponding complete set)
5.1.12. Removal and installation of an additional heater of STH (at the corresponding complete set)
5.1.13. Removal and installation of the circulating pump of an additional heater of STH (at the corresponding complete set)
5.2. Systems of ventilation, heating and air conditioning
6. A power supply system and production of the fulfilled gases
7. Systems of electric equipment of the engine
8. Automatic transmission
9. Transmission line
10. Brake and auxiliary systems
11. Suspension bracket and steering
12. Body
13. Onboard electric equipment
14. Schemes of electric connections



5.1.4. Thermostat check

Check without thermostat removal


  1. Before removing and checking operability of the thermostat, be convinced that problems with cooling of the engine arose not owing to insufficient amount of cooling liquid or a weak tension of a driving belt. Be convinced of serviceability of the indicator located on a combination of devices.
  2. If the engine long gets warm to working temperature (according to indicator indications), the thermostat, possibly, is jammed in open situation. In this case it is necessary to replace the thermostat.
  3. On the other hand, long warming up can be a consequence of lack of the thermostat. It could be made specially or inadvertently (forgot to establish after repair). Do not use the car without the thermostat. The control system of the engine will support more long a mode of warming up of the unit in which the engine consumes more fuel, and the fulfilled gases contain bigger amount of harmful impurity.
  4. If the engine overheats, touch the top hose of a radiator. If it not hot, but the engine перегрет, the thermostat, probably, jammed in a closed position. Liquid does not get to a radiator and circulates on a small circle. In this case replace the thermostat.
  5. If the top hose of a radiator hot, it means that the thermostat is open and liquid normally circulates on system, - familiarize with the recommendations provided in the Section Diagnostics of malfunctions.

Check with thermostat removal

Check of serviceability of functioning of the thermostat

1 — the Thermostat

2 — Tarelchaty the valve


  1. Remove the thermostat (see. Section Removal and thermostat installation).
  2. If the thermostat at room temperature is abroach - it is faulty and is subject to replacement.
  3. For rough check of operability of the thermostat suspend it on a piece of a twine in capacity with water. The thermostat should not concern capacity walls. Start to heat up capacity.

From the moment of achievement in temperature of value on 8°С below a point of the beginning of opening of the valve speed of heating should make no more 1-2°æ/minute.

  1. In process of water heating the thermostat should open (it occurs directly ahead of water boiling). As the temperature of boiling of water makes 100°С, the thermostat can not open completely (see. Specifications). Take the thermostat and let's to it cool down, - the valve should be closed completely.
  2. If the thermostat does not open when heating or is not closed when cooling, replace it.
  3. At installation of the thermostat pay attention to the next moments:
  1. Track, that interfaced surfaces were smoothed carefully out, do not forget to prepare and establish a new sealing ring;
  2. Track correctness of orientation of the thermostat in a casing;
  3. Track, that bolts of fastening of a cover were tightened with demanded effort (see. Specifications);
  4. Filling of system of cooling (see. Head the Current leaving and service) begin only having made sure of correctness of connection of all hoses;
  5. On termination of installation start the engine, warm up to normal working temperature and make sure of lack of signs of development of leaks.

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5.1.3. Check of a cover of system of cooling, replacement of hoses of system of cooling
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5.1.5. Removal and thermostat installation