For information on replacing spark plugs, please refer to the materials in the Section Checking and replacing spark plugs.
Manufacturers recommend a specific type of spark plug, but you can use suitable spark plugs with the appropriate heat rating from other manufacturers.
It is advisable to clean spark plugs with a sandblaster every 20,000 km. In this case, set the appropriate interelectrode distance if conventional spark plugs are used (with one ground electrode). When adjusting the distance, never bend the middle electrode, as this may cause the porcelain insulator to crack.
Before unscrewing the spark plugs, check that there are no foreign objects in the spark plug recesses. Washers, bolts or stones that get into the spark plug holes will destroy the valves, valve seats or cylinder head when the engine is first started.
By the appearance of the candle, you can make a conclusion about the operation of the candles, the operation of the injection system, the state of the mixture and the condition of the engine (pistons, piston rings, etc.).
Since the spark plug replacement interval is 40,000 km, it is sufficient to clean them every 20,000 km. When screwing in the spark plugs, make sure that they are not overtightened, as this may damage the sealing washer. Do not exceed a tightening torque of 25 N·m.