Oily deposits on the flower plug are the entry of lubricating oil, and the upper end of the insulator may be broken due to low gasoline label. When maintaining a car, you should pay more attention to the condition of the spark plug. The spark plug with excellent performance can improve the dynamic performance of the vehicle. Under normal circumstances, the service life of spark plugs is 15000 kilometers, and the service life of long-lasting spark plugs does not exceed 30000 kilometers. However, many car owners' spark plugs often have problems of one kind or another, which cannot reach their normal service life.

In fact, the working temperature of the spark plug is quite high. When the engine is running normally, the temperature of the spark plug insulator skirt is generally maintained between 500 and 600 degrees Celsius. Too high or too low temperature has a bad effect on spark plugs. When the temperature of the spark plug is too low, the insulator on the spark plug is prone to carbon deposits, causing leakage and even misfire. If the working temperature of the spark plug is too high, it is easy to cause pre-ignition and engine knock. In the Chery Auto Training Camp, the staff of the store summarized the common faults of spark plugs into two types. One is that the spark plug is severely ablated, and the other is that the spark plug has deposits.

spark plug ablation

When the car owner finds that the upper end of the spark plug is scarred or damaged, and the electrode is melted or ablated, it indicates that the spark plug has been destroyed, and the spark plug should be replaced at this time. During the replacement process, the owner can check the symptoms of spark plug ablation and color changes.

Symptom 1: The electrode is melted and the insulator is white

Diagnosis: This phenomenon indicates that the temperature in the combustion chamber is too high. This may be caused by excessive carbon deposits in the combustion chamber, which causes the valve clearance to be too small, which further causes the exhaust valve to overheat or the cooling device to work poorly. When the spark plug is not tightened according to the specified torque, the electrode will melt and the insulator will appear white.

Symptom 2: The electrode is rounded and the insulator is scarred

Diagnosis: This indicates that the engine pre-ignition may be caused by premature ignition time or low gasoline octane number and high spark plug calorific value.

Symptom 3: The upper end of the insulator is broken

Diagnosis: Generally speaking, detonation combustion is the main cause of insulator rupture. The ignition time is too early, the gasoline octane number is low, and the temperature in the combustion chamber is too high, which may cause the engine to knock and burn.

Symptom 4: There are gray-black stripes on the upper end of the insulator

Diagnosis: The appearance of this stripe indicates that the spark plug has leaked, and the owner needs to replace it with a new one unconditionally