The working process of diesel automobile engine has some specific features that determine the nature of his work at low temperatures. These features are manifested in the deterioration of fuel atomization, the viscosity of which increases as a result of lower temperature. To ensure a start in cold season of the modern diesel engines are equipped with glow plugs. Candles carry out a preliminary heating of the air inside the cylinder, which enables engine starting at low ambient temperatures.

To ensure trouble-free operation of the diesel engine in the winter suggests a regular check of the glow plugs. Testing candles is a standard procedure in the comprehensive health check of diesel engine carried out by the specialists of the service stations of cars. In the presence of certain knowledge and skills, check the glow plug, the car owner can perform on their own.


Test a glow plug of a diesel engine can be performed in two ways – test voltage a closed circuit and a visual method.

Check voltage



As a tool to control the use of a voltmeter or an ohmmeter. In the absence of the instrument testing can be performed using led lamp, one lead wire which is connected with the positive pole of the battery and the other is in turn connected to each of the candles.

Check visual method



Before checking turned the nozzle of one of the cylinders, so that the resulting hole could be seen the glow plug. This method involves two people. One reviewer from the driver's seat turns the key in the ignition, while the other observed the behavior of the glow plugs. If the candle is serviceable, it should glow red hot.

This method is not applicable to all models of cars, as in some engines, the spark is not visible through the hole of the nozzle. In this case you should use the first method.

If the candle is difficult to eversion, the place of its planting, gently soak with kerosene or solvent. After the end of the test should be installed, pre-lubricated the threads with grease. If during testing will be identified inefficient candles, they must be replaced.