E30 series BMW 3

since 1983-1994 of release

Repair and car operation

+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engine
- 4. Cooling system
   4.2. Specifications
   4.3. Antifreeze
   4.4. Thermostat
   4.5. Radiator
   4.6. Fans and drive coupling
   4.7. The pump of cooling liquid
   4.8. The sensor of temperature of cooling liquid
+ 5. Heating and ventilation
+ 6. Fuel system
+ 7. Exhaust system
+ 8. Transmissions
+ 9. Coupling
+ 10. Brake system
+ 11. Running gear
+ 12. Body
+ 13. Electric equipment
+ 14. Good advice


4.4. Thermostat


Collars of hoses on the case of the thermostat of the 4-cylinder engine

Thermostat branch pipe on the 6-cylinder engine

The thermostat case, the thermostat and sealing ring are removed.

The correct arrangement of the thermostat on a final branch pipe of system of cooling (the 6-cylinder engine)

The label in the form of an arrow should be turned up. Bolts of fastening to tighten with the moment 9±1 N of m.


If the engine long gets warm, it is necessary to replace the thermostat. Previously check liquid level, a condition of a belt of a drive of the pump and serviceability of the sensor and the temperature index.

Also it is necessary to replace the thermostat, if on the heated-up engine the top hose of a radiator the cold.


1. Disconnect the battery from weight and merge cooling liquid.
M10 engine
2. Remove the fan.
3. Release collars of the bottom hose of a radiator and get the thermostat.
4. Installation is carried out upside-down.
M20 engine

5. Release a collar and disconnect hoses from thermostat branch pipes.
V.Datchik of liquid temperature
6. If the branch pipe of the thermostat is damaged by corrosion, the thermostat replace.
7. Unscrew bolts and remove the thermostat case.
8. Remove the thermostat.

9. Remove the remains of consolidation or remove laying of the case of the thermostat.
10. Replace laying, establish the new thermostat and attach a hose.
M40 engine
11. Remove the fan and the top cover of a gear belt.
12. Release a collar and disconnect the bottom hose from a knee in a forward part of a head of cylinders.
12. Unscrew bolts and remove a branch pipe.
13. Get the thermostat.
14. Establish the new thermostat and replace laying. Assembly is carried out upside-down.