🔧 Fusion - Ignition Coil Replacement

On your Fusion, each cylinder has its own ignition coil mounted on top of the spark plug (called “coil-on-plug”). Replacing a bad coil is a common fix for a misfire, rough idle, flashing check-engine light, or loss of power.

Difficulty Level: Beginner | Estimated Time: 0.5-1.0 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a cool engine; coils sit near hot components.
• ⚠️ Keep tools away from any orange high-voltage cables (hybrid system). You will not be servicing the HV system for this job.
• ⚠️ If you disconnect the 12V battery, you may lose radio presets and clock settings.
• ⚠️ Recommended: disconnect the 12V negative battery terminal before unplugging ignition components.

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🔧 Required Tools

You'll need the following tools for this repair:

• 8mm socket
• 1/4" drive ratchet
• 3" extension (1/4" drive)
• 10mm wrench
• Trim removal tool (plastic)
• Torque wrench (in-lb)
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1 (or Qty: 4 if replacing all)
• Dielectric grease - Qty: 1

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📋 Before You Begin

• Park on level ground and power the car OFF.
• Open the hood and let the engine cool.
• Disconnect the 12V battery negative terminal: use a 10mm wrench to loosen the negative clamp and move it aside so it can’t spring back. (The 12V battery is in the trunk area on your Fusion.)
• Tip: Take a quick photo of connectors first.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover

• Grip the cover at the corners and pull straight upward to release the rubber grommets.
• If it feels stuck, use a trim removal tool (plastic) to gently lift at a corner.

Step 2: Locate the ignition coils

• The coils are the 4 identical units lined up on top of the engine valve cover.
• Each coil has an electrical connector and a small hold-down bolt.

Step 3: Unplug the coil electrical connector

• Press the connector lock tab and pull the connector straight off the coil by hand.
• If the tab is stubborn, gently assist with a trim removal tool (plastic)—don’t pry hard on the wires.
• Tip: Pull the connector body, not the harness.

Step 4: Remove the coil hold-down bolt

• Use an 8mm socket with a 1/4" drive ratchet and 3" extension to remove the coil bolt.
• Set the bolt aside where it won’t fall into the engine bay.

Step 5: Remove the ignition coil

• Grab the coil and twist it gently left-right to break the seal.
• Pull straight upward to remove it from the spark plug well.
• If it’s stuck, keep twisting while pulling—avoid using metal pry tools.

Step 6: Install the new ignition coil

• Apply a very thin smear of dielectric grease inside the new coil boot (the rubber part). (Dielectric grease helps prevent moisture and makes future removal easier.)
• Push the coil straight down until you feel it fully seat on the spark plug.

Step 7: Reinstall and torque the coil bolt

• Thread the bolt in by hand first to avoid cross-threading.
• Use an 8mm socket to snug it down.
• Use a torque wrench (in-lb): Torque to 62 in-lb (7 Nm).

Step 8: Reconnect the coil connector

• Push the connector on until it clicks/locks.
• Do a gentle tug-check to confirm it’s fully seated.

Step 9: Reinstall the engine cover and reconnect the 12V battery

• Press the engine cover back down onto the grommets until it seats evenly.
• Reconnect the 12V negative terminal using a 10mm wrench and tighten securely.

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✅ After Repair

• Start your Fusion and let it idle for 1-2 minutes. It should run smooth with no shaking.
• If you had a check-engine light, it may take a few drive cycles to go out on its own; best practice is to clear the code with a scan tool.
• Test drive 10-15 minutes with gentle acceleration and confirm no misfire, no flashing check-engine light, and normal power.
• Recheck that all coil connectors are fully clicked in if the engine still runs rough.

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💰 DIY vs Shop Cost

Shop Cost: $200-$600 (parts + labor, depending on how many coils)

DIY Cost: $40-$320 (parts only, depending on how many coils)

You Save: $160-$280 by doing it yourself!

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

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🎯 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.