Bad spark plugs: signs to be aware of

1、 Power attenuation: a visual signal of weak acceleration

As the core component of engine ignition, spark plugs, once aged or carbon deposits, can lead to insufficient ignition energy and incomplete combustion of fuel. The most obvious manifestation is the slow response and weak power output of the vehicle during acceleration. Even if the accelerator is pressed deeply, the speed is difficult to increase quickly, especially when overtaking or climbing at high speeds, this sense of powerlessness will be more prominent. This is because insufficient combustion leads to a decrease in power conversion rate, which not only affects the driving experience but also indirectly increases fuel consumption.

2、 Idle shaking and difficulty starting: typical manifestations of abnormal ignition

A normally functioning engine runs smoothly at idle. If the spark plug malfunctions, the ignition timing is disrupted, or some cylinders do not ignite, it can cause the engine to shake violently at idle, and the body vibration can be clearly felt while sitting in the car. The dashboard pointer may also fluctuate accordingly. In addition, multiple ignitions are required to start the vehicle during cold start, and even startup failure may occur. This is a common sign of spark plug wear, excessive electrode gap, or severe carbon deposition, especially in low-temperature environments where this problem becomes more frequent.

3、 Soaring fuel consumption and abnormal exhaust: a chain reaction of insufficient combustion

When the spark plug cannot ignite effectively, the fuel cannot be completely burned and will be discharged, directly leading to a significant increase in fuel consumption. Some models may increase fuel consumption by 10% -20%. At the same time, unburned fuel can cause abnormal exhaust color, such as black smoke and pungent fuel odor, which not only pollutes the environment but may also lead to unqualified exhaust testing. If such a situation occurs, it is necessary to check the status of the spark plug in a timely manner to avoid further expansion of the fault.

4、 Engine abnormal noise and malfunction light alarm: serious signals that cannot be ignored

When the spark plug malfunction is severe, it may cause the engine to make a "bang bang" knocking sound or irregular abnormal noise, which is due to unstable fuel combustion in the combustion chamber, and even delayed combustion phenomenon. What needs to be more vigilant is that the engine malfunction light is on, and at this time, the on-board computer has detected an abnormality in the ignition system. If driving continues, it may cause damage to the ignition coil, increase carbon buildup in the cylinder, and even cause engine cylinder shortage, resulting in greater repair costs. It is recommended to immediately go to a repair shop for maintenance after this sign appears.