How to judge the working condition of the engine by the color of the spark plug?

- Feb 21, 2019 -

How to judge the working condition of the engine by the color of the spark plug?

The normal color of the electrode of the spark plug is brownish white. If the electrode is black and has carbon deposits, it indicates a fault.

Ordinary car spark plug replacement cycle is about 30,000 kilometers, depending on the material of the spark plug, the replacement mileage is also different. In order to avoid unnecessary trouble, it is best to replace the spark plug as required.

During the inspection, the spark plug can be connected to the cylinder block, the terminal block of the spark plug is touched by the central high-voltage line, and then the ignition switch is turned on to observe the high-voltage electric jump position. If the electric jump position is in the spark plug gap, the spark plug works well; otherwise, a new one is needed.

The spark plug has a serious carbon deposit - the oil flows into the combustion chamber, commonly known as burning oil.

The spark plug is stuck with sand - there is a problem with the air filter seal, the sand enters the combustion chamber, and the sand melts on the spark plug under the action of high temperature.

The spark plug is white - the mixture is too lean, causing the engine to overheat. Long-term non-treatment will cause serious engine failure.

Black velvety carbon deposits - air filter is too dirty, oil pressure regulator vacuum tube is broken, gasoline pressure is too high, oxygen sensor is damaged, electronic control system is faulty, etc.

The center electrode is rounded--the spark plug is used for too long, so the spark plug consumes a lot of power when it is ignited, and it also causes the engine to work poorly.

The center electrode is shortened - the spark plug is not replaced during maintenance.

Surface ablation - the spark plug heat value is incorrectly matched, the ignition angle is too early, the mixture gas is lean, the cooling system temperature is too high, and the lubrication system lacks oil.