To clean spark plugs effectively, first remove them safely from the engine when it has cooled down. Clean the outside to remove debris, and then use one of several methods depending on the condition of the plugs:
- Abrasive Cleaning: Use 220-grit sandpaper or a wire brush to gently sand or scrub away carbon deposits and buildup on the electrode and threads until bare metal is visible. This removes fouling that prevents proper spark.
- Blow Torch Method: Use a butane blowtorch or small torch to heat the spark plug electrodes briefly, burning off oil, carbon, and residue. Let it cool, then brush off leftover residue with a soft bristle brush.
- Spark Plug Cleaner Tool: Use a pneumatic or electric spark plug cleaner with abrasive media like silica sand inside a cotton bag, blasting deposits off the plug. Follow by blowing dust off with compressed air.
After cleaning, check and adjust the spark plug gap to your car manufacturer’s specifications using a gap tool. Apply a small amount of anti-seize compound or grease to the threads before reinstalling. Tighten the spark plugs to the correct torque setting with a torque wrench to avoid issues. If the spark plugs are severely worn, cracked, or damaged, it’s better to replace them. Cleaning can restore fouled but otherwise good spark plugs and save money on replacements.