What are the precautions for replacing spark plugs?
2 Answers
Precautions for replacing spark plugs are as follows: 1. Before replacement, turn off the vehicle and let it cool down. 2. Before removing the spark plugs, clean any debris and dust around the spark plug holes. 3. When disconnecting the high-voltage wires from the spark plugs, mark each cylinder for reference. 4. The spark plug electrodes and seals must be kept clean, dry, and free from oil contamination. 5. If the spark plug does not thread in smoothly during installation, remove it to identify the cause before reinstallation. Do not force tighten it blindly. 6. Tighten the spark plugs to the specified torque. Too loose may cause air leakage, while too tight may cause the sealing gasket to lose elasticity. 7. The selected spark plugs should match the vehicle's requirements; otherwise, poor ignition may occur. 8. When replacing spark plugs, try to use high-quality spark plugs with premium metal electrodes (such as platinum or iridium). 9. During installation, apply anti-seize compound to the threads (or use spark plugs with pre-coated threads) to make future removal easier.
With decades of driving experience, I’ve got plenty of know-how on changing spark plugs, and here are the key tips to share: Always turn off the engine and disconnect the negative battery cable before starting to avoid sparks or short circuits. Use the right-sized socket and a torque wrench, tightening gently to avoid stripping the threads. Buy new spark plugs strictly according to your vehicle’s manual—wrong brands or materials can hurt ignition efficiency and fuel economy. Clean the spark plug holes to prevent dust or debris from falling in, and use a feeler gauge to adjust the gap to around 0.7-1mm for optimal performance. After installation, start the engine to check if the idle is smooth and listen for unusual noises—address any issues immediately. Neglecting spark plug replacement leads to poor acceleration, and I’ve seen severe carbon buildup damage engines firsthand. Inspect them every 20,000 km as a safety measure—never cut corners to save money or effort.
