Oily deposits on the spark plug are lubricating oil entering, and the tip of the insulator is broken may be a low gasoline grade. When maintaining the 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 15,000 kilometers, and the service life of long-term spark plugs does not exceed 30,000 kilometers. However, many car owners’ spark plugs often have problems of one kind or another, and their normal service life is not reached.
In fact, the working temperature of the spark plug is quite high. During normal engine operation, 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 the spark plug. When the temperature of the spark plug is too low, the insulator on the spark plug is prone to carbon deposition, which will eventually cause leakage and lead to a misfire phenomenon. If the working temperature of the spark plug is too high, it is easy to cause pre-ignition and engine knocking. In the Chery training camp, the staff of the specialty store classified 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 top of the spark plug has scars or damage, and the electrodes are melted and ablated, it means that the spark plug has been damaged. The spark plugs should be replaced at this point. Owners can check for signs of spark plug ablation and color changes during the replacement process.
Symptom 1: Melted Electrode and White Insulator
Diagnosis: This phenomenon indicates that the temperature in the combustion chamber is too high. This may be caused by too much carbon deposition in the combustion chamber, resulting in too small valve clearance, further causing overheating of the exhaust valve or poor operation of the cooling device. When the spark plug is not tightened according to the specified torque, the electrode will also melt, and the insulator will appear white.
Symptom 2: Electrodes are rounded and insulator knots are scarred
Diagnosis: This is an indication of premature engine ignition, either too early ignition or too much gasoline The alkane number is too low, the calorific value of the spark plug is too high, etc.
Symptom 3: Cracked Insulator Tip
Diagnosis: Generally, detonation combustion is the primary 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: Gray-black stripes on the top 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.
Deposit on Spark Plug
Deposit can sometimes build up between the tip of the spark plug insulator and the electrode. Owners should not underestimate such deposits. In severe cases, this condition may cause the engine to not work properly. After cleaning the spark plugs, the vehicle can run normally for a while, but something similar will happen again shortly after. In fact, spark plug deposits are just a superficial phenomenon that could signal a problem with other mechanical parts of the vehicle.