What are the precautions for spark plug replacement?
2 Answers
Precautions for spark plug replacement include: When installing spark plugs, a specialized torque wrench should be used to tighten them. If the spark plug is not tightened sufficiently, it may cause cylinder leakage. Conversely, if the spark plug is overtightened, it may lead to breakage. The spark plug is a crucial component of the gasoline engine's ignition system, responsible for introducing high-voltage electricity into the combustion chamber and generating a spark across the electrode gap to ignite the combustible air-fuel mixture in the cylinder. The method for replacing spark plugs is as follows: 1. Wait for the engine to cool completely, open the hood, disconnect the ignition coil connector, then use a socket to remove the ignition coil to access the spark plug; 2. Select a socket based on the size of the spark plug nut and turn it counterclockwise to loosen, then use a magnetic rod to extract the spark plug; 3. Use the magnetic rod to hold the new spark plug and place it into the hole, then follow the reverse steps above for installation.
I often change spark plugs myself, and the most important things are safe operation and thorough preparation. The engine must be completely cooled for several hours—never work on a hot engine, or you might get burned. Disconnecting the negative battery terminal is a must to prevent accidental short circuits. Choosing spark plugs isn’t something to take lightly—check the vehicle manual or confirm the model number to ensure the heat range and gap match the engine, or you risk poor ignition and even engine damage. When removing them, use a dedicated wrench and work gently to avoid debris falling into the installation hole. Before installing new spark plugs, inspect the electrodes and threads, and make sure the sealing ring is intact. I use a torque wrench to tighten them to 15-20 Nm—too tight or too loose is bad. For a four-cylinder engine, I start with the first cylinder to avoid confusion. After installation, start the engine and listen for smooth ignition sounds; delayed ignition usually points to a gap issue. Regular replacement saves fuel and boosts performance—inspecting every 20,000-30,000 km is a good habit that saves money and builds knowledge.
