What to Do When the Spark Plug Cannot Be Removed?
2 Answers
There are several methods to remove a stuck spark plug: 1. Welding Method: Weld a thin, long iron bolt onto the broken spark plug head, then remove the broken spark plug. This method usually requires multiple welding attempts to succeed and is relatively difficult. 2. Reverse Thread Tool: Since broken spark plugs are a common occurrence, specialized reverse thread tools for removing broken spark plugs are widely available. Here’s how to use a reverse thread tool: (1) Use the reverse thread tool to tap threads inside the broken spark plug head, then twist the tool to remove the broken piece. (2) During the threading process, fine metal shavings may fall into the cylinder. After removing the broken piece, use a magnetic rod to clean them out as much as possible. Spark plugs typically have a lifespan of around 100,000 kilometers, so they don’t need frequent replacement. However, since spark plugs function deep inside the cylinder, they must endure immense pressure and temperature. Experiments show that the pressure during combustion can reach up to 5,000 kPa, and temperatures can soar to 2,000 degrees Celsius. Therefore, even if they don’t need frequent replacement, regular inspections are essential.
When a spark plug can't be removed, it's usually due to thread corrosion seizing or adhesion caused by high engine temperature. I've encountered this situation frequently before, and the solution is quite simple: spray some WD-40 or other penetrating oil around the threads, wait 5-10 minutes for it to seep in and lubricate, then slowly loosen it with a professional spark plug socket wrench. Never use an ordinary wrench to force it, as this can easily cause thread stripping or breakage inside, making the problem worse. If the tool isn't suitable, try again with the correct wrench. If the engine is still warm, wait until it's completely cooled before removal, otherwise thermal expansion will make it tighter. If it really won't budge, don't force it – if the spark plug is severely stuck, you might need to remove the cylinder head, in which case it's best to go to a professional shop to avoid making a mess. Poor spark plug maintenance is the root cause, and regular inspection and replacement can prevent this. Remember, safety first – be careful of burns or damaging parts when working in the engine compartment.
