Can Spark Plugs Be Tightened by Hand?
2 Answers
Spark plugs can be tightened by hand, and then further tightened with a socket wrench. Steps for replacing spark plugs: Open the engine hood, lift the plastic cover of the engine, remove the high-voltage ignition wires, and mark each cylinder's position 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 they are thoroughly cleaned. Place the new spark plug into the spark plug hole, hand-tighten it a few turns, and then use a socket wrench to tighten it further. Reinstall the high-voltage ignition wires according to the firing order and 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's advisable to follow the owner's manual. Below are general guidelines for 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.
I've been driving for over a decade. When I first started changing spark plugs myself, I thought hand-tightening was sufficient—just wrenching them until they wouldn't budge. However, after that instance, my car shook violently upon starting. A shop diagnosis revealed that loose spark plugs caused gas leakage and misfiring. The technician explained that spark plugs must be precisely torqued with a torque wrench. Too loose, and compressed gas leaks, disrupting engine smoothness; too tight, and you risk stripping threads or deforming electrodes, potentially damaging the cylinder head long-term. Since then, I've kept a small toolkit and always torque them to around 20 N·m as recommended by the manual. DIY maintenance is fun, but details make or break it—don’t cut corners and regret it later. Good habits ensure more reliable vehicle performance.
