🔧 Explorer - Ignition Coil Replacement

This is a manageable job, and the front three coils are especially straightforward. Your Explorer uses six coil-on-plug units, meaning each spark plug has its own ignition coil. Ford confirms this ignition layout for the 3.5L EcoBoost. fordservicecontent.com

Replace only the diagnosed bad coil unless several have failed or you want a complete matched set. I'd inspect the spark plugs while the coils are out because a worn plug can overwork a new coil. Nobody likes doing the same job twice.

Difficulty Level: Beginner to Intermediate | Estimated Time: 1-2 hours

Assumption: This procedure covers coil replacement without removing the intake manifold.

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⚠️ Safety & Precautions

• ⚠️ Let the engine cool completely before touching the coils or turbo plumbing.
• ⚠️ Keep dirt, loose hardware, and tools away from the spark-plug openings.
• ⚠️ Never pull a coil connector while the engine is running.
• ⚠️ Disconnect the negative battery cable before unplugging multiple ignition coils.
• ⚠️ Pull on the coil body, not its rubber boot or wiring.

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🔧 Required Tools

You'll need the following tools for this repair:

• 8mm socket
• 10mm socket
• 1/4-inch drive ratchet
• 1/4-inch drive 3-inch extension
• 1/4-inch drive 6-inch extension
• 1/4-inch drive universal joint
• Inch-pound torque wrench (20-150 in-lbs)
• Plastic trim removal tool
• Small flat-blade screwdriver
• Compressed-air blow gun
• Fender cover
• Nitrile gloves
• Safety glasses

A universal joint is a small hinged socket adapter that helps reach fasteners at an angle.

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Coil-on-plug ignition coil - Qty: 1 per failed cylinder, or 6 for a complete set
• Ignition coil connector - Qty: As needed if a locking tab or terminal is damaged
• Dielectric silicone grease - Qty: 1 small tube
• Spark plugs - Qty: 6 if inspection shows excessive wear, cracking, or incorrect gap

The ignition-coil aisle is open beside this guide. Use the vehicle-filtered listing rather than choosing solely by price because several coil families appear in the catalog.

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📋 Before You Begin

• 📋 Park your Explorer on level ground, select Park, and apply the parking brake.
• 📋 Switch off the ignition and keep the key away from the vehicle.
• 📋 Wait until the engine is cool enough to touch comfortably.
• 📋 Record any diagnostic trouble codes before disconnecting the battery.
• 📋 Label each connector if you're replacing all six coils.
• 📋 Disconnect the negative battery terminal using a 10mm socket.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the Engine Appearance Cover

• Lift the engine cover evenly at its mounting points using both hands.
• If a fastener is fitted, remove it with an 8mm or 10mm socket before lifting.
• Set the cover where its rubber mounting grommets won't be lost.

Step 2: Create Working Room

• Use a small flat-blade screwdriver to release any intake-tube clamp or retaining clip blocking the selected coil.
• Use an 8mm socket if the intake hose uses a worm-drive clamp.
• Move only the necessary intake tube or wiring retainer aside. Don't disconnect coolant or fuel lines.
• For a rear-bank coil, use the 6-inch extension and universal joint to work below the cowl.

Step 3: Clean Around the Coil

• Put on safety glasses.
• Use the compressed-air blow gun to clear sand and debris from the coil and spark-plug well.
• Check for engine oil or water around the coil. Fluid in the well must be corrected before installing the new coil.

Step 4: Disconnect the Electrical Connector

• Slide or lift the connector lock with the small flat-blade screwdriver, if equipped.
• Press the release tab and pull the connector straight from the coil by its plastic housing.
• Inspect the connector for a broken lock, green corrosion, heat damage, or loose terminals.
• Don't pry against the fragile connector wires.

Step 5: Remove the Ignition Coil

• Use the 8mm socket, extension, and 1/4-inch ratchet to remove the coil retaining bolt.
• Grip the coil body and gently rotate it a few degrees to release the rubber boot.
• Pull the coil straight upward. A rear coil may need to be tilted slightly after the boot clears the spark plug.

Step 6: Inspect the Removed Coil and Spark-Plug Well

• Check the rubber boot for white tracking lines, splits, swelling, oil saturation, or burned spots.
• Use the compressed-air blow gun again if debris remains inside the well.
• If you're diagnosing a misfire, compare the removed coil with the neighboring coils before discarding it.
• Don't remove the spark plug unless you have the proper spark-plug socket and confirmed replacement procedure.

Step 7: Prepare the Replacement Coil

• Compare the electrical connector, bolt flange, boot length, and overall shape with the removed coil.
• Apply a very thin film of dielectric silicone grease inside the opening at the bottom of the rubber boot.
• Keep grease away from the electrical terminals and the spark plug's metal contact.

Step 8: Install the Replacement Coil

• Lower the coil squarely over the spark plug by hand.
• Press downward until the boot seats firmly on the spark-plug terminal.
• Start the retaining bolt by hand to avoid cross-threading the aluminum cylinder head.
• Use the inch-pound torque wrench and 8mm socket to tighten the bolt to 8 Nm (71 in-lbs).
• Do not exceed this torque without checking Ford service information for the installed bolt.

Step 9: Reconnect the Coil

• Push the electrical connector onto the coil until its release tab clicks.
• Re-engage the secondary connector lock, if equipped.
• Give the plastic connector housing a light pull to confirm it's locked.

Step 10: Repeat for Additional Coils

• Repeat Steps 3 through 9 for each remaining coil.
• Replace one coil at a time so connectors and components can't be mixed up.
• Keep every coil well covered until its new coil is installed.

Step 11: Reassemble the Engine Compartment

• Reinstall any intake tube or wiring retainers moved for access.
• Use the 8mm socket to tighten an intake hose clamp until secure without crushing the plastic tube.
• Reinstall the engine cover by aligning its mounts and pressing down evenly.
• Use the 10mm socket to reconnect the negative battery terminal securely.

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✅ After Repair

• ✅ Check that no tools, rags, or loose connectors remain in the engine compartment.
• ✅ Start the engine and let it idle while listening for smooth, even operation.
• ✅ If the check-engine light flashes or the engine shakes badly, switch it off and recheck every connector.
• ✅ Use a scan tool to clear stored misfire codes only after recording them.
• ✅ Road-test gently and rescan for pending codes after the engine reaches operating temperature.
• ✅ If the same-cylinder misfire returns, test the spark plug, connector, injector, wiring, and cylinder compression rather than installing another coil.

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💰 DIY vs Shop Cost

Shop Cost: $180-$350 for one accessible coil, or $650-$1,100 for all six

DIY Cost: Approximately $25-$90 per coil, or $220-$530 for a set

You Save: Approximately $100-$550 by doing it yourself!

Local labor rates vary considerably. Rear-bank access and diagnostic time can increase the total.

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