Mazda 626

1991-1998 of release

Repair and operation of the car

Mazda 626

+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engines
- 4. Heating and ventilation
   4.1. Introduction
   4.2. Technical characteristics
   4.3. Thermostat
   4.4. The cooling fans
   4.5. Radiator and broad tank
   4.6. Water pump
   4.7. Sensor of temperature of cooling liquid
   4.8. Oil heater of the engine (6-cylinder models)
   4.9. Electric chain of the motor of the delivery fan
   4.10. Motor of the delivery fan
   4.11. Control unit of a heater and air conditioner
   4.12. Heater radiator
   + 4.13. Systems of air conditioning and heating
+ 5. Fuel system
+ 6. Exhaust system
+ 7. Transmissions
+ 8. Coupling and half shafts
+ 9. Brake system
+ 10. Running gear
+ 11. Body
+ 12. Electric equipment
+ 13. Electrical circuitries
+ 14. Useful tips


4.3. Thermostat



The engine has to cool down completely.


1. Measure the level of cooling liquid, check a tension of a driving belt and functioning of the temperature sensor.
2. If the engine is warmed too long, most likely, that jammed the thermostat in open situation. Replace the thermostat.
3. If the engine overheats, check temperature of the top hose of a radiator if not the hot, so thermostat jammed a hose in a closed position. Replace the thermostat.
4. For conducting more careful check the thermostat needs to be removed from the engine.
5. If the thermostat is not closed at the room temperature, so it is faulty and is subject to replacement.
6. Lower the thermostat in the container with cold water (the thermostat is closed).
7. Warm up water in capacity and you watch its temperature. The thermostat should not concern walls and a bottom of capacity.
8. Write down indications of the thermometer when the thermostat only begins to open and when it is completely open. Compare the received sizes to technical requirements.
9. Replace the thermostat if it does not open or is not closed or jams it in any situation.


1. Disconnect a wire of the minus plug of the accumulator.
2. Merge cooling liquid from a radiator. In six-cylinder engines remove an airintaking branch pipe.
3. Disconnect a hose of a radiator (A) and unscrew bolts from a cover of the thermostat (V) – 4-cylinder models.
4. Unscrew a bolt (V) of a tube of cooling liquid. Disconnect a tube from a cover of the thermostat and unscrew bolts of a cover (A) – 6-cylinder models.
5. Uncover the thermostat.
6. Remove the thermostat.
7. Clean the joined surfaces and establish new laying.
8. Installation is carried out upside-down removals.

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