Where is the car spark plug located in the car?

[DelHope]

Car spark plugs are installed on the side or top of the engine. In early models, spark plugs were connected to the distributor via ignition cables. Over the past decade, most passenger car engines have been modified to have ignition coils directly connected to the spark plugs. Working principle of spark plugs: The ground electrode of a spark plug is connected to the metal shell, which is threaded into the engine block through the cylinder head. The insulator primarily serves to isolate the metal shell from the center electrode. The terminal nut is the part of the spark plug that contacts the high-voltage coil. When current passes through the terminal nut and center electrode, it ionizes the medium between the center electrode and ground electrode to generate a spark, thereby igniting the air-fuel mixture in the cylinder. If a spark plug is damaged, it can directly cause multiple issues such as ignition system leakage, increased fuel consumption, and reduced power output. The most significant problem is difficulty in ignition, affecting normal vehicle operation. Severe spark plug erosion - including scarring at the tip, damage, or melted/eroded electrodes - indicates that the spark plug has failed and should be replaced.