Tools You'll Need:
* Socket wrench set: You'll need a socket that fits your spark plugs (likely 5/8" or 13/16", but check your owner's manual). A ratchet and extensions will be helpful for better access.
* Spark plug socket: This has a rubber insert to grip the spark plug without damaging it.
* Torque wrench: Crucial for tightening the spark plugs to the correct specification. Over-tightening can damage the threads, while under-tightening can lead to misfires.
* Gloves: To keep your hands clean.
* Penetrating oil (like PB Blaster): This can help loosen stubborn plugs.
* Wrench for the coil packs (if applicable): The Aztec likely uses coil packs over individual plug wires. You'll need a wrench to remove these.
* New spark plugs: Make sure you get the correct type and heat range for your engine. Consult your owner's manual or a parts store.
* Shop rags or paper towels: To clean up any spills or debris.
Steps:
1. Safety First: Disconnect the negative terminal from your car battery. This prevents accidental shorts and injury.
2. Locate the Spark Plugs: Consult your owner's manual to find the location of the spark plugs. They're usually located on top of the engine, often under plastic covers or coil packs.
3. Remove the Coil Packs (if applicable): If your Aztec uses coil packs, carefully disconnect the electrical connectors from each coil pack. Then, use the appropriate wrench to remove the coil packs. Take note of their position so you can reinstall them correctly.
4. Clean the Area: Clean around the spark plug wells using compressed air or a shop rag to prevent debris from falling into the cylinder.
5. Remove the Old Spark Plugs: Use the spark plug socket to carefully remove the old spark plugs. Spray penetrating oil on the plugs if they're difficult to remove, allowing it to sit for a few minutes. Turn the socket counter-clockwise. Avoid dropping the old plugs into the cylinder.
6. Inspect the Old Spark Plugs: Examine the old plugs for signs of wear, fouling, or damage. This can help diagnose potential engine issues.
7. Install the New Spark Plugs: Carefully install the new spark plugs by hand, screwing them in until they're snug. Then, use the spark plug socket and torque wrench to tighten them to the manufacturer's specified torque. Do not over-tighten.
8. Reinstall the Coil Packs (if applicable): Carefully reinstall the coil packs, ensuring the electrical connectors are securely attached.
9. Reconnect the Battery: Reconnect the negative battery terminal.
10. Start the Engine: Start the engine and listen for any unusual noises or misfires.
Important Considerations:
* Torque Specifications: This is crucial! Over-tightening can strip the threads, and under-tightening can lead to misfires. Use a torque wrench and refer to your owner's manual for the correct specification.
* Gap: Spark plugs have a gap. If the plugs are pre-gapped, you likely don't need to adjust it. If not, you’ll need a spark plug gapping tool. The gap needs to be correct for proper ignition.
* Heat Range: Use the correct heat range spark plugs for your engine. Using the wrong heat range can lead to premature wear or engine damage.
* If you're uncomfortable performing this task yourself, take your vehicle to a qualified mechanic. It's better to pay a professional than risk damaging your engine.
This is a complex process, and this guide is for informational purposes only. Always consult your owner's manual and seek professional assistance if needed. Incorrect installation can lead to serious engine problems.
