1. Assess the Situation:
* How much is broken? Is just the porcelain tip broken off, or is the entire plug sheared off flush with the cylinder head? This dictates the approach.
* Access: How accessible is the spark plug? Some are easier to reach than others.
* Tools: Gather the necessary tools *before* you start. Improvising mid-job is frustrating and can worsen the problem.
2. Methods (from least to most invasive):
* Penetrating Oil: If the plug is still somewhat protruding, liberally apply a penetrating oil (like PB Blaster or Liquid Wrench) to the threads. Let it soak for several hours, or even overnight. This can help loosen corrosion and rust. Reapply as needed. Then try removing with a spark plug socket. Use a ratchet, not a wrench, to avoid stripping the plug.
* Spark Plug Extractor: This is a specialized tool with a reverse-threaded bit that grabs onto the broken plug. Different types are available – some use a claw-like grip, others screw into the remaining threads. Choose the one best suited to your situation. This is often the most effective method for partially broken plugs. Important: Use the correct size extractor for your spark plug thread size.
* Easy-Out (Screw Extractor): Similar to a spark plug extractor, but often more robust for tougher situations. These can be effective if the extractor mentioned above doesn't work. Be careful to avoid stripping the cylinder head. Use penetrating oil liberally.
* Drilling & Extracting: This is the most invasive option and should be a last resort. It involves carefully drilling a pilot hole into the center of the broken plug, then using a specialized extractor designed for this purpose (an "easy-out" with an extra-fine tip). This is a very risky method and requires precision to avoid damaging the cylinder head threads. If you lack experience, strongly consider professional help. Drilling too deep can damage the engine block, and improperly placed holes can damage your engine.
3. General Tips:
* Patience is Key: Rushing this process will likely lead to more damage. Take your time and be methodical.
* Cleanliness: Keep the area around the spark plug clean to avoid debris falling into the cylinder.
* Protective Gear: Wear safety glasses and gloves.
* Torque Wrench: Once the broken plug is out, use a torque wrench to install the new plug to the manufacturer's specified torque. Over-tightening can easily damage the threads.
* Professional Help: If you're uncomfortable with any of these methods, or if the plug is completely flush with the cylinder head, take it to a qualified mechanic. The cost of repair will be far less than the cost of engine damage.
Specific to a 1992 Cavalier: The engine type (e.g., 1.8L, 2.0L, 2.2L, 2.5L V6) will influence accessibility. Consult a repair manual specific to your Cavalier's engine to identify the spark plug location and size, and torque specifications for tightening the new plug. This is crucial to avoid damage and ensure proper functioning.
Remember: Safety first. If you are not comfortable working on your car's engine, seek professional help. A damaged engine block or cylinder head is a far more expensive repair than paying a mechanic.
