Here's a general overview. Specific steps may vary slightly depending on the year and engine of your Expedition:
Tools You'll Need:
* New spark plugs: Get the correct type and heat range recommended in your owner's manual.
* Socket wrench set: You'll need a deep well socket that fits your spark plugs (usually 5/8" or 13/16", but check your manual). A ratchet is also essential.
* Spark plug socket: This is a special socket with a rubber insert to grip the spark plug without damaging it.
* Extension(s): To reach the spark plugs in the back of the engine.
* Wrench: For the coil pack mounting bolts (if applicable).
* Gloves: To protect your hands.
* Penetrating oil (like PB Blaster): To help loosen stubborn plugs.
* Torque wrench: Absolutely critical to tighten the plugs to the correct specification. Over-tightening can easily damage the threads in the engine block.
* Shop rags or paper towels: To clean up.
* Optional: Magnetic pickup tool to retrieve dropped spark plugs.
Procedure (General Steps):
1. Safety First: Disconnect the negative battery cable before starting any work.
2. Locate Spark Plugs: Consult your owner's manual for the location of the spark plugs. They are typically located on top of the engine, but access might be difficult depending on the engine configuration.
3. Access the Spark Plugs: This is often the most challenging part. You might need to remove parts like:
* Air intake system: This often needs to be removed or at least partially disconnected.
* Coil packs: Many Ford Expeditions use coil packs that cover the spark plugs. You'll need to remove the coil packs, usually by unscrewing or unplugging them. Be careful not to damage the coil pack connectors.
* Other components: Depending on your engine, you might have to remove other components to gain better access.
4. Remove the Old Spark Plugs: Spray penetrating oil on the spark plugs and let it sit for a few minutes. Use the spark plug socket and ratchet to carefully remove the old spark plugs. Turn them counter-clockwise. Be careful not to drop them into the engine cylinder.
5. Inspect the Old Spark Plugs: Examine the old spark plugs for wear and tear. This can give you an indication of engine problems.
6. Install the New Spark Plugs: Carefully install the new spark plugs by hand, making sure they are seated correctly. Then, use the spark plug socket and torque wrench to tighten them to the manufacturer's specified torque. Do not overtighten.
7. Reassemble Everything: Carefully reinstall the coil packs (if applicable), air intake system, and any other components you removed.
8. Reconnect the Battery: Reconnect the negative battery cable.
9. Start the Engine: Start the engine and listen for any unusual noises or misfires.
Important Considerations:
* Gap: Some spark plugs may need to be gapped to the correct measurement using a spark plug gapping tool. Check your owner's manual or the new spark plug packaging.
* Difficulty of Access: Accessing the spark plugs can be very difficult depending on the year and engine of your Ford Expedition. Be prepared to spend some time working on this.
* Professional Help: If you are not comfortable performing this task, it's best to take your Expedition to a qualified mechanic.
This is a general guideline. Always consult your Ford Expedition's owner's manual for detailed instructions specific to your vehicle. Improperly installed spark plugs can lead to engine damage. Remember safety first, and if in doubt, seek professional help.
