- Check the condition of the porcelain insulator for cracks. With the engine cold, remove the ignition coils (KZ), by labeling them first. Blow out the spark plug wells with compressed air, you can use a regular bicycle pump. Sequential replacement of SZ is recommended. Unscrew the SZ with a special candle key, turning it counterclockwise.
- Compare the condition of the removed spark plug with standard options to assess the condition of the engine:
- the gray color of the electrodes and the insulator of medium density indicates the normal operation of the candles and the fuel mixture preparation system;
- the black color of the electrodes and insulator indicates that the mixture is too rich;
- the light gray color of the electrodes and insulator indicates that the mixture is too lean;
- oiling of the electrodes and insulator indicates that the candles are intermittent or there is increased wear on the piston rings.
- Check the spark plug insulator for traces of leakage currents, which are visible as thin random marks on the surface of the insulator. The reason for the appearance of traces is poor contact in the plug of the candle. This plug connection (ShS) replace.
- Apply a thin layer of anti-seize compound to the threads of the new spark plugs, install the spark plug into the holes in the cylinder head and turn it by hand until it stops. Using the socket of the spark plug wrench and torque wrench, tighten the spark plug to 25 N.m (2.5 kgf·m). Install the ignition short in its place. Replace the remaining CVs as described above.