Attention! Wait until the engine has completely cooled down before proceeding with the procedure!
Examination
1. The device for indicating the temperature of the coolant consists of a meter mounted in the instrument panel of the car and a temperature sensor mounted on the engine block, directly below the ignition distributor (4-cylinder models) or housing-mounted thermostat (V6 models). On some models, more than one temperature sensor may be provided, but only one of them is always used in the display system.
Attention! The vehicles covered in this manual are equipped with electric fans for cooling and air conditioning systems. Try not to put your hands near the fan impellers, which, when the ignition is on, can suddenly work even when the engine is turned off.
2. If the meter shows overheating even with a definitely cold engine, check the wiring between the instrument panel and the temperature sensor for signs of a short circuit.
3. If the meter does not function at all, check the condition of its electrical circuit by quickly shorting the wire leading to the temperature sensor to ground with the ignition on (the engine must not be started). If the indicator needle deviates to the end of the scale, replace the sensor.
Attention! Try not to touch the fan blades of the cooling system, which can turn on even when the engine is turned off!
4. If the arrow remains motionless, check for an open circuit in the meter circuit.
5. In the absence of confidence in the serviceability of the temperature sensor, measure its electrical resistance with a cold and hot engine. The sensor resistance should change inversely with the temperature measurement and with a cold engine (below 57°С) be about 137 ohms. As the engine warms up, the resistance of the sensor should gradually decrease and at a temperature of 86÷101°С reach a value in the range of 30÷46 Ohm. A defective sensor must be replaced.
Replacement
To replace the temperature sensor, simply unscrew it from the engine and quickly screw a new one into the vacated hole, the threads of which should be lubricated with sealant in advance (do not try to use Teflon tape or FUM tape to seal the sensor fit).
Attention! The temperature sensor must be replaced with a cold engine! Prepare to collect spilled liquid. After replacing the sensor, check the coolant level and correct if necessary (see chapter Settings and ongoing maintenance).