Spark plug analysis (Hyundai Elantra XD)

Visual inspection of the working part of the spark plugs can indicate the condition of the engine.

If the nose of the insulator is covered with a black coating, this indicates that the mixture is too rich. If the coating is black and oily, this indicates engine wear and the need for inspection and repair. If the nose of the insulator is covered with a light brown coating, then the mixture composition is optimal and the engine is in good condition.

If the nose of the spark plug insulator is clean and white, without any coating, then this indicates that the mixture is too lean. This also indicates that the spark plug is too hot, meaning that heat is being slowly removed from the center electrode. If this is the case, it is necessary to adjust the fuel mixture or replace the spark plug.

(The original material is located on the website www.hyundaibook.ru)