Why can't the spark plug be pulled out?
2 Answers
The reason why the spark plug cannot be pulled out is: When removing the spark plug for the first time, the rubber cap of the ignition wire is relatively tight, making it difficult to pull out. You need to wiggle the base of the ignition wire cap to loosen it, then pull it vertically upward with force, and the ignition wire will come off. When installing the spark plug, use the rubber sleeve of the ignition wire as well. Be careful not to insert it randomly, as it may bend the discharge head, which will affect the ignition effect. The spark plug is an important component of the gasoline engine ignition system. It introduces high voltage electricity into the combustion chamber and makes it jump across the electrode gap to generate a spark, thereby igniting the combustible mixture in the cylinder. The spark plug mainly consists of a terminal nut, insulator, terminal stud, center electrode, side electrode, and shell, with the side electrode welded to the shell.
I've been driving for over 30 years, and the most common culprits when spark plugs won't come out are thread corrosion or high-temperature bonding. When the engine is running at high temperatures, chemical reactions occur between the spark plug metal and the cylinder block material in the heated state, causing them to stick together. The solution is to first wait for the engine to completely cool down, then spray some specialized rust penetrant like WD-40 and let it soak for five to ten minutes to penetrate. Gently turn the spark plug wrench left and right—don't use brute force, as this can easily snap the spark plug or damage the cylinder head threads. Preventive measures include regular maintenance, checking spark plug condition every two years, and applying high-temperature anti-seize lubricant when installing new spark plugs. A damp engine bay environment accelerates corrosion, so keeping it clean is crucial. Forcing it out might double your repair costs—don't take it lightly.
