Where is the spark plug installed?
2 Answers
The spark plug is installed on the side or top of the engine. In early designs, spark plugs were connected to the distributor via ignition cables. However, over the past decade, most car engines have been updated to feature direct connections between the ignition coil and the spark plug. 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 via the cylinder head. The insulator primarily serves to isolate the metal shell from the central 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 central electrode, it ionizes the medium between the central electrode and ground electrode to generate a spark, thereby igniting the air-fuel mixture in the cylinder. Spark plug replacement interval: Under normal maintenance conditions, replacement is recommended every 40,000–60,000 kilometers. However, this may vary depending on the brand and engine type, so always consult the owner's manual. For reference, follow these maintenance standards: Platinum spark plugs: replace at 40,000 km. Standard nickel alloy spark plugs: replace at 20,000 km. Iridium spark plugs: replace at 60,000–80,000 km.
When I first learned to drive, I was really curious about the location of the spark plugs. Actually, they are installed at the top of the engine, with one spark plug for each cylinder, positioned slightly inward and inserted into the cylinder head facing the combustion chamber. The first time I replaced the spark plugs, I foolishly thought they could be installed anywhere, but being even slightly off in position caused them to fail to ignite properly, leaving the car unable to start. Now I understand that the positioning is quite deliberate—the spark plugs must be precisely aligned to produce a strong spark to ignite the air-fuel mixture. Otherwise, the engine loses power or fuel consumption skyrockets. It's recommended to check them every 20,000 to 30,000 kilometers. Don't wait until the car breaks down to panic. Keeping a spark plug wrench at home makes it easy to replace them yourself—simple and hassle-free.
