1. Safety First:
* Disconnect the negative battery terminal. This prevents accidental shorts and protects your electronics.
* Let the engine cool completely. Hot spark plugs can cause burns.
2. Gather Your Tools:
* Spark plug socket: The correct size (usually 5/8" or 13/16" depending on the year - check your manual) with a rubber insert to prevent rounding the spark plug.
* Wrench or ratchet: To turn the spark plug socket. A swivel extension can be very helpful to access tighter plugs.
* Spark plug gap tool (optional): To check the gap of new spark plugs.
* Penetrating oil (optional): If you anticipate difficult removal, spray some penetrating oil around the base of the spark plugs and let it sit for a while.
* Shop rags or paper towels: To keep the area clean.
3. Locate the Spark Plugs:
* The spark plugs are located on top of the engine, towards the center. However, their exact location and accessibility can be hindered by other components. You'll need to consult a repair manual or online diagrams specific to your year and engine for the precise location of each spark plug.
4. Remove the Spark Plugs:
* Carefully remove any wire or boot connected to each spark plug. It's best to mark each wire (or take a picture) to ensure you re-install them correctly. Some boots may have a clip you need to release before pulling the wire.
* Position the spark plug socket over the spark plug. Make sure the rubber insert is securely gripping the spark plug.
* Slowly and steadily unscrew the spark plug. Use a counter-clockwise rotation. If it's stuck, try using a little more penetrating oil and letting it sit, or gently rocking the socket back and forth while turning. Avoid excessive force to prevent damaging the spark plug or the threads in the cylinder head.
* Remove the spark plug and set it aside in a safe place, preferably in the order they were removed. You may want to mark them to identify which cylinder they came from.
5. Install New Spark Plugs (if replacing):
* Clean the spark plug wells with compressed air or a suitable brush. This removes any debris that could interfere with the new plug's seal.
* Inspect the new spark plugs (if applicable). Make sure the gap is correct (check your owner's manual or the plug packaging for specifications)
* Thread the new spark plugs by hand initially, several turns. Ensure they are going in straight.
* Finish tightening the new spark plugs with the spark plug socket and wrench. Do not overtighten. Refer to your repair manual for the proper torque specification. Overtightening can damage the spark plug and cylinder head threads.
Important Considerations:
* Repair Manual: A repair manual specific to your Fiero's year and engine is essential. It will provide detailed diagrams, torque specifications, and specific instructions that are crucial for proper repair.
* Difficulty: Accessing some of the spark plugs on a Fiero's six-cylinder engine might be challenging due to limited space.
* Professional Help: If you're uncomfortable with this procedure, consider seeking professional assistance from a qualified mechanic.
Remember, this is a general guide. Always consult your vehicle's repair manual for specific instructions and torque specifications. Improper procedures can damage your engine.
