🔧 Fusion - Ignition Coil Replacement

Replacing the ignition coils on your Fusion is a straightforward top-of-engine repair. The ignition coils create the high voltage needed to fire the spark plugs, and a bad coil can cause misfires, rough running, poor fuel economy, or a check engine light.

Difficulty Level: Beginner | Estimated Time: 30-60 minutes

---

⚠️ Safety & Precautions

• ⚠️ Your Fusion is a plug-in hybrid, but this repair is on the gasoline engine ignition system, not the high-voltage hybrid battery system.
• ⚠️ Do not touch any orange high-voltage cables or hybrid battery components.
• ⚠️ Let the engine cool before starting so you do not burn your hands on the valve cover or exhaust-side components.
• ⚠️ Disconnect the 12-volt negative battery cable before unplugging ignition coils to reduce the chance of electrical shorts.
• ⚠️ Keep dirt and debris out of the spark plug wells. Anything that falls in can damage the engine.

---

🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 8mm socket
• 1/4-inch drive ratchet
• 3/8-inch drive ratchet
• 6-inch extension
• Torque wrench inch-pound range
• Trim clip removal tool
• Compressed air nozzle
• Dielectric grease applicator brush
• Nitrile gloves
• Safety glasses

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1-4
• Dielectric grease - Qty: 1 small tube

Tip: If one coil failed, you can replace only that coil. If mileage is high, replacing all four as a set can prevent repeat misfire repairs.

---

📋 Before You Begin

• 🅿️ Park your Fusion on level ground and shift to Park.
• 🔌 Turn the vehicle fully OFF and remove the key/fob from the cabin area.
• 🧊 Let the engine cool for at least 30 minutes.
• 🔋 Open the hood and disconnect the 12-volt negative battery cable using a 10mm socket.
• 🧰 A torque wrench is a tool that tightens bolts to an exact tightness so small fasteners are not broken.
• 💨 Compressed air is used to blow dirt away before parts are removed.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Open the Hood and Make the Engine Safe

• Use your hand to release the hood latch and raise the hood.
• Use the hood prop rod or hood supports to secure the hood.
• Use a 10mm socket and 3/8-inch drive ratchet to loosen the negative 12-volt battery cable clamp.
• Move the negative cable aside so it cannot spring back onto the battery terminal.
• Keep metal tools away from battery terminals.

Step 2: Remove the Engine Cover

• If equipped, lift the plastic engine appearance cover straight upward by hand.
• If any clips resist, use a trim clip removal tool gently around the cover mounting points.
• Set the cover aside where it will not be stepped on.

Step 3: Locate the Ignition Coils

• The four ignition coils sit in a row on top of the engine valve cover.
• Each coil has an electrical connector and one small retaining bolt.
• If replacing only one coil, match the coil location to the misfire cylinder code if you have one.
• Cylinder numbering on the 2.0L inline-4 is typically from the belt/front side of the engine toward the transmission side: cylinders 1, 2, 3, and 4.

Step 4: Clean Around the Coils

• Put on safety glasses.
• Use a compressed air nozzle to blow dust and grit away from the top of the valve cover and around each ignition coil.
• Do not aim debris toward your face.
• Clean first. Remove parts second.

Step 5: Unplug the Ignition Coil Connector

• Press the locking tab on the electrical connector with your thumb.
• Pull the connector straight back from the ignition coil.
• If the connector is stuck, gently wiggle it by hand while pressing the tab.
• Do not pull on the wires.

Step 6: Remove the Ignition Coil Bolt

• Use an 8mm socket, 6-inch extension, and 1/4-inch drive ratchet to remove the coil retaining bolt.
• Place the bolt in a tray or safe spot so it does not fall into the engine bay.
• If removing multiple coils, work one coil at a time to avoid mixing positions.

Step 7: Remove the Old Ignition Coil

• Grip the ignition coil body by hand.
• Twist the coil gently left and right to loosen the rubber boot from the spark plug.
• Pull the coil straight upward out of the spark plug well.
• Inspect the old coil boot for oil, cracking, carbon tracking, or moisture.
• Carbon tracking means a black lightning-like mark where spark has been leaking.

Step 8: Prepare the New Ignition Coil

• Compare the new ignition coil to the old one by hand before installing it.
• Use a dielectric grease applicator brush to apply a very small amount of dielectric grease inside the end of the rubber boot.
• Dielectric grease is a non-conductive silicone grease that helps seal moisture out of the boot.
• Do not pack the boot full of grease.
• A pea-sized amount is plenty.

Step 9: Install the New Ignition Coil

• Slide the new ignition coil straight down into the spark plug well by hand.
• Push firmly until you feel the boot seat onto the spark plug.
• Make sure the bolt hole lines up with the valve cover mounting point.

Step 10: Tighten the Ignition Coil Bolt

• Start the retaining bolt by hand first to avoid cross-threading.
• Use an 8mm socket, 6-inch extension, and torque wrench inch-pound range to tighten the bolt.
• Torque to 6 Nm (53 in-lbs).
• Do not overtighten. The valve cover threads can be damaged.

Step 11: Reconnect the Electrical Connector

• Push the electrical connector onto the ignition coil until it clicks.
• Gently tug the connector by hand to confirm it is locked.
• Repeat Steps 5-11 for any other ignition coils being replaced.

Step 12: Reinstall the Engine Cover

• Set the engine cover back over its mounting points by hand.
• Press down firmly until the cover seats fully.
• If clips were removed, use the trim clip removal tool only as needed to align them gently.

Step 13: Reconnect the 12-Volt Battery

• Place the negative battery cable back onto the battery terminal.
• Use a 10mm socket and 3/8-inch drive ratchet to snug the clamp.
• Torque to 5 Nm (44 in-lbs) if using a torque wrench with the correct range.
• Make sure the clamp does not rotate by hand after tightening.

---

✅ After Repair

• ✅ Start your Fusion and let the gasoline engine run if possible.
• ✅ Listen for smooth idle and check that no connectors are loose.
• ✅ If the check engine light was on, clear diagnostic trouble codes with a scan tool after the repair.
• ✅ Test drive gently for 10-15 minutes and confirm the misfire, shaking, or hesitation is gone.
• ✅ If the same cylinder misfire returns, inspect the spark plug, injector, wiring, and compression before replacing more coils.

---

💰 DIY vs Shop Cost

Shop Cost: $180-$550 depending on whether one coil or all four are replaced

DIY Cost: $45-$280 parts only

You Save: $100-$270 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1.0 hour.

---

🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.