"Diagnosing" cars through the condition of spark plugs

1. Brownish yellow spark plug

A yellow-brown spark plug indicates that the engine is operating normally, the fuel/air ratio is within technical standards and the mechanical components are stable.

If you replace spark plugs, use spark plugs with the same heat range (with the same length of the ceramic insulator underneath). Longer heat range spark plugs work hotter and shorter heat range spark plugs work cooler.

2. White spark plug

This condition occurs on many car models, indicating that the car engine is overheating. The cause of this condition may be due to an unsuitable spark plug (too large a temperature range), the fuel octane rating is too low, the engine ignition timing is not optimal, the engine cooling system is damaged, or the engine is starved of gasoline (too much air).

In this case, it is necessary to find out the cause and fix it by trying to replace the spark plug, adjust related systems...

3. Black and dry spark plug

When checking and seeing that the spark plugs are black, it is likely that the engine is running in a fuel-rich mode (excess gasoline) or the car is idling too much. For models that also have black smoke coming out of the exhaust pipe, it is exactly because the engine is running too much gasoline.

This phenomenon can be caused by a number of reasons such as: dirty air filter leading to blockage causing insufficient air supply to achieve the standard mixture ratio, broken carburetor, stuck air choke, weak spark plug so it does not burn all the air mixture. Before replacing the spark plug, it is necessary to adjust the appropriate air mixture ratio, clean the air filter, air choke...

4. The negative spark plug is badly worn.

This happens because the spark plug is affected by the effects of additives in gasoline and engine oil.

When the above condition occurs, the engine will lose fire, especially when accelerating because the ignition gap between the two spark plug electrodes is large, causing poor ignition voltage, the vehiclealso has difficulty starting; you should replace the spark plugs.

5. Spark plugs have a large spark gap

If the driver uses the spark plug for too long without replacing it, the ignition process will wear out the center electrode, increase the spark gap and reduce the spark plug's ignition ability, causing a decrease in engine power. In this case, you should replace the spark plug for better engine performance.

6. Spark plug with broken ceramic tip

Mostly due to mechanical impact, when the spark plug is dropped or heavy weight is placed on the spark plug center pole due to misuse. It can also be due to long-term use that the spark plug has deposits on the spark plug ceramic tip and center pole and the center pole is rusted.

Such spark plug condition will cause loss of fire, late ignition compared to fuel injection timing, reducing engine power.

7. Spark plug electrode melt

In this case, the spark plug will have a local melt at the center or melt completely, the ceramic tip will also be pitted or cracked. The cause of the above phenomenon is due to automatic ignition causing overheating, the spark plug has an inappropriate temperature range, or other causes such as: combustible residue in the combustion chamber, damaged coil, damaged valve, poor fuel quality; willcausing misfire and reducing engine power.

In this case, check the coil, engine, fuel ratio and replace the spark plugs.

8. Melted spark plug poles

When the spark plug is melted on both poles and has foreign substances on the spark plug pole, it is due to the spark plug overheating due to auto-ignition. Pre-ignition, damaged coil, damaged valve, poor quality gasoline or combustible deposits in the combustion chamber also cause the above phenomenon.

This condition will cause loss of ignition and reduce engine power, causing damage to the vehicle's engine. You need to check the engine, fuel quality, and ignition coil before replacing the new spark plugs.