🔧 F-150 - Spark Plug Replacement

Replacing the spark plugs on your F-150 helps restore smooth idle, fuel economy, and proper ignition under boost. The 2.7L EcoBoost uses six spark plugs, one under each ignition coil.

Difficulty Level: Intermediate | Estimated Time: 1.5-2.5 hours

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⚠️ Safety & Precautions

• ⚠️ Work only on a completely cool engine to avoid burns and damaged aluminum cylinder head threads.
• ⚠️ Disconnect the negative battery cable before unplugging ignition coils.
• ⚠️ Do not use anti-seize on the new spark plug threads unless the plug manufacturer specifically requires it.
• ⚠️ Start every spark plug by hand first. Cross-threading means the plug is going in crooked and can damage the cylinder head.
• ⚠️ Keep dirt out of the spark plug wells. A plug well is the deep tube where the spark plug sits.

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🔧 Required Tools

You'll need the following tools for this repair:

• 8mm socket
• 10mm socket
• 3/8-inch drive ratchet
• 3/8-inch drive torque wrench
• 5/8-inch spark plug socket
• 6-inch 3/8-inch drive extension
• 3-inch 3/8-inch drive extension
• 3/8-inch drive universal joint
• Flat-blade screwdriver
• Plastic trim tool
• Compressed air blow gun
• Spark plug gap gauge
• Dielectric grease
• Shop vacuum
• Mechanic gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs - Qty: 6
• Ignition coil boots - Qty: 6

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📋 Before You Begin

• 🅿️ Park your F-150 on level ground, shift to Park, and set the parking brake.
• 🧊 Let the engine cool fully. A cool engine protects the aluminum spark plug threads.
• 🔋 Use a 10mm socket to disconnect the negative battery cable and move it aside so it cannot spring back.
• 🧼 Clean loose dirt from the engine cover and ignition coil area before opening anything.
• 📏 Check the new spark plug gaps with a spark plug gap gauge. A gap gauge measures the small opening at the tip of the plug.
• ✅ Use only spark plugs specified for the 2.7L EcoBoost. Turbo engines are sensitive to plug type and gap.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the Engine Cover

• Use your hands to lift the engine cover straight upward from the rubber mounting grommets.
• If it feels stuck, use a plastic trim tool to gently lift near each mounting point.
• Set the cover aside where it will not get stepped on.
• Lift evenly, not sideways.

Step 2: Clear Access to the Ignition Coils

• Use a flat-blade screwdriver to loosen any intake tube clamps blocking access.
• Use an 8mm socket to remove small brackets or fasteners that block the coil area, if equipped.
• Move hoses and wiring gently by hand only as far as needed.
• Do not pull hard on plastic connectors. They can become brittle with heat.

Step 3: Clean Around the Coils

• Put on safety glasses.
• Use compressed air blow gun to blow dirt away from the top of each ignition coil.
• Use a shop vacuum to remove loose debris around the valve covers.
• This helps keep dirt from falling into the spark plug wells.

Step 4: Disconnect One Ignition Coil Connector

• Work on one cylinder at a time so parts do not get mixed up.
• Use your finger or a plastic trim tool to release the locking tab on the ignition coil electrical connector.
• Pull the connector straight back from the coil.
• Do not pull on the wires.

Step 5: Remove the Ignition Coil

• Use an 8mm socket and ratchet to remove the ignition coil hold-down bolt.
• Twist the ignition coil gently by hand to loosen the rubber boot.
• Pull the coil straight upward and set it aside in order.
• If replacing coil boots, pull the old boot off the coil by hand.

Step 6: Blow Out the Spark Plug Well

• Use compressed air blow gun to blow out the spark plug well before removing the plug.
• A spark plug well is the deep hole where the plug sits.
• Keep your face away from the well while using compressed air.

Step 7: Remove the Old Spark Plug

• Use a 5/8-inch spark plug socket, 6-inch extension, and 3/8-inch drive ratchet to loosen the spark plug.
• For tight rear plugs, use a 3-inch extension and 3/8-inch drive universal joint. A universal joint lets the socket bend slightly.
• Turn counterclockwise slowly until the plug is free.
• Lift the plug out using the spark plug socket.
• If the plug feels unusually tight, stop and tighten it slightly, then loosen again slowly.

Step 8: Inspect and Gap the New Spark Plug

• Use a spark plug gap gauge to verify the new spark plug gap.
• Use the gap listed on the underhood emissions label if available.
• Do not forcefully pry on fine-wire iridium plug tips.
• Do not apply anti-seize unless the spark plug manufacturer specifically says to.

Step 9: Install the New Spark Plug by Hand

• Place the new spark plug into the 5/8-inch spark plug socket.
• Use only the extension by hand at first, with no ratchet attached.
• Turn clockwise gently until the plug seats.
• If it does not turn easily, remove it and start again.
• Hand-starting prevents thread damage.

Step 10: Torque the Spark Plug

• Attach the 3/8-inch drive torque wrench to the extension and spark plug socket.
• Tighten the spark plug to Torque to 15 Nm (11 ft-lbs).
• Do not overtighten. The cylinder head is aluminum.

Step 11: Install the Coil Boot and Ignition Coil

• If replacing the boot, push the new ignition coil boot onto the ignition coil by hand.
• Apply a small amount of dielectric grease inside the end of the boot.
• Dielectric grease is an electrical-safe grease that helps seal out moisture.
• Push the ignition coil straight down onto the spark plug until fully seated.

Step 12: Reinstall the Coil Bolt and Connector

• Use an 8mm socket and ratchet to install the ignition coil hold-down bolt.
• Tighten the coil bolt to Torque to 8 Nm (71 in-lbs).
• Push the electrical connector onto the coil until it clicks.
• Lightly tug the connector to confirm it is locked.

Step 13: Repeat for the Remaining Five Spark Plugs

• Repeat Steps 4 through 12 for each remaining ignition coil and spark plug.
• Use the 3/8-inch drive universal joint for the rear plugs if access is angled.
• Keep each coil matched to its original cylinder unless you are replacing coils.

Step 14: Reinstall Removed Intake Pieces and Brackets

• Use an 8mm socket to reinstall any brackets or fasteners removed earlier.
• Use a flat-blade screwdriver to tighten intake tube clamps securely.
• Make sure all hoses and wiring are back in their original positions.

Step 15: Reinstall the Engine Cover and Battery Cable

• Push the engine cover straight down onto its rubber grommets by hand.
• Use a 10mm socket to reconnect the negative battery cable.
• Tighten the negative battery cable nut snugly. Do not overtighten it.

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✅ After Repair

• ✅ Start the engine and let it idle for 2-3 minutes.
• ✅ Listen for a smooth idle with no popping, ticking from loose plugs, or misfire shaking.
• ✅ Check that every ignition coil connector is fully clicked in.
• ✅ Take a short test drive with light throttle first, then moderate acceleration.
• ✅ If the check engine light flashes, stop driving and recheck coil connectors and plug installation.
• ✅ Some idle relearn may occur after the battery is disconnected. This usually settles after a short drive.

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💰 DIY vs Shop Cost

Shop Cost: $300-$550 (parts + labor)

DIY Cost: $60-$160 (parts only)

You Save: $240-$390 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-2.0 hours.

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🎯 Ready to get started?

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