What Causes Engine Shaking After Replacing Spark Plugs?
2 Answers
The reason for engine shaking after replacing spark plugs is that the spark plugs are not tightened properly. Therefore, the force used when replacing spark plugs should be based on the required torque for the specific spark plugs being used, as spark plugs of different sizes require different amounts of force. Steps for replacing spark plugs: Open the engine hood, lift the plastic cover of the engine, and remove the high-voltage distributor wires. Mark the position of each cylinder to avoid confusion. Use a spark plug socket to remove the spark plugs one by one. While removing them, check for any external debris like leaves or dust and ensure everything is cleaned thoroughly. Place the new spark plugs into the spark plug holes, hand-tighten them a few turns, and then use the socket to tighten them further. Reinstall the removed high-voltage distributor wires according to the firing order, and then secure the cover. Spark plug replacement interval: Under normal maintenance conditions, spark plugs should be replaced every 40,000 to 60,000 kilometers. However, this may vary depending on the brand and engine type, so it is recommended to follow the user manual. The following standards can be used as a reference for maintenance and replacement: Platinum spark plugs should be replaced at 40,000 kilometers, standard nickel alloy spark plugs at 20,000 kilometers, and iridium spark plugs at 60,000 to 80,000 kilometers.
As someone who enjoys studying car maintenance, I often encounter this shaking issue when helping others replace spark plugs. Common causes include improper installation or incorrect torque of the spark plugs, leading to poor sealing and air leaks; or the replacement model being incompatible with the original vehicle, such as differences in heat range or gap causing ignition abnormalities. Another possibility is accidentally disturbing the ignition coils or wiring during the operation, resulting in loose connections. Additionally, the quality of the spark plugs cannot be ignored, as inferior parts are prone to early failure and affect combustion. Lastly, the engine ECU needs to readjust to the new spark plugs, and if not properly matched, it may also cause shaking. When addressing the issue, first check if the installation is correct and the model matches. Otherwise, it's advisable to visit a professional shop for a diagnostic scan to avoid damaging the engine by driving it forcefully.
