5.9. Check of serviceability of functioning and replacement of the block of the sensor of the measuring instrument of temperature of cooling liquid

Before starting implementation of the procedure wait for full cooling of the engine!


The device of indication of temperature of cooling liquid consists of the car of the measuring instrument and the sensor of temperature installed on the engine block, directly under the ignition distributor which is built in in an instrument guard (see an illustration below).


 PERFORMANCE ORDER

1. If the measuring instrument shows an overheat even at unambiguously cold engine, it is necessary to check an electrical wiring between the dashboard and the sensor of temperature for existence of signs of short circuit.
2. If the measuring instrument does not function at all, check a condition of its electric contour, having quickly short-circuited on weight the wire going to temperature sensor at the included ignition (the engine should not be started). If the arrow of the indicator to deviate until the end of a scale, replace the sensor. If the arrow remains motionless, check a measuring instrument chain electrical wiring for break.

Try not to touch cooling system fan blades which can turn on even at the killed engine!


3. In the absence of confidence in serviceability of the sensor of temperature, measure its electric resistance at cold and at the hot engine. Resistance of the sensor has to change in inverse proportion to measurement of temperature and at the cold engine (below 55 °C) to make about 140 Ohms. In process of an engine warming up resistance of the sensor has to decrease gradually and at a temperature of 86 °C to reach value in the range of 30÷46 Ohms.
4. For replacement of the sensor of temperature just turn out it from the engine and quickly screw in the released opening new which carving should be greased with sealant beforehand. Prepare for collecting the spilled liquid. Having replaced the sensor, check the level of cooling liquid, in case of need make the corresponding adjustment (see the Head Routine maintenance).

Replacement of the sensor of temperature has to be made on the cold engine!