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


4.8. The sensor of temperature of cooling liquid


The sensor of temperature of cooling liquid (violet-brown wire) on the 4-cylinder engine

The sensor of temperature of cooling liquid (violet-brown wire) on the 6-cylinder engine

The sensor (or the index) are checked by check of their resistance and connection with weight (if this connection is provided by an electric circuit, see subsection 13.2.4).

To establish malfunction of the sensor, the index or conducting it is possible on the basis of the following simple checks. If the arrow of the index of temperature is near an initial mark of a scale in the heated-up engine, disconnect the socket from the sensor and at the included ignition connect a crossing point a socket conclusion to weight. If thus the arrow of the index moved to an extreme part of a scale, the sensor replace. Otherwise are faulty either conducting or the index. If indications of temperature are obviously overestimated on the cold engine, and at a socket detachment from the sensor of the shooter comes back to initial situation, the sensor is faulty. If the provision of an arrow does not change, in a wire or in the index there is a short circuit on weight.

On the M40 engine the sensor of temperature will screw in the left part of a head of cylinders. On other engines the sensor as a rule will screw in the thermostat case. On a part of cars 2 sensors, only one of which are provided works with the index.

At replacement of the sensor some loss of liquid is possible. The new sensor wrap on hermetic.