Type of spark plug (VW Golf 2)

By the appearance of a spark plug that has been in operation for a long time (at least 1000 km from the moment of installation on the engine), you can determine the quality of its operation, whether the fuel level in the carburetor is adjusted, the composition of the mixture and the condition of the engine (piston clearances, etc.). The engine should not idle before checking the spark plugs, as the spark plug will be covered with black sediment. To properly assess the spark plug condition, it is necessary to drive at least 20 km. The engine will then warm up sufficiently, and the spark plug operating conditions will be determined.

A spark plug that works properly

The lower part of the insulator is white-gray, even to light brown shades. Light powdery coating on the lower part of the insulator and on the electrodes, which can be easily removed or cleaned with a brush.

From the inside, the body is light gray or covered with sediment ranging in color from yellowish to dark brown.

Conclusion: The engine is in good condition. The spark plug size is selected correctly.

Dirty spark plug

The lower part of the insulator, the electrodes and the body of the spark plug are covered with a sediment in the form of a large, dark gray silky powder.

Cause: Very rich mixture. Incorrect carburetor installation, poor starting equipment, very long driving on choke. Spark plug heat value is very high. Driving on very short sections of the track.



Conclusion:Install the carburetor correctly. Check the engine. If necessary, use spark plugs of a lower heat value

Oiled candle

The lower part of the insulator, the electrodes and the body of the spark plug are covered with an oily, shiny soot.

Cause: Too much oil in the combustion chamber. Piston rings, cylinders and valve guides are worn out.

Conclusion: Repair the engine. Install new spark plugs.

The spark plug is overheated

The central electrode is slightly melted, blistered, spongy, softened top of the lower part of the insulator. The color of the lower part of the insulator is mainly pale gray, on the top there are growths and small pearls (slightly melted).

Cause: Thermal value is very low. The spark plug is not pressed enough. Glow ignitions due to oil sediment.

Conclusion: Install spark plugs with normal heat rating.