🔧 Focus - Ignition Coil Replacement

Replacing the ignition coils on your Focus restores strong spark to the engine and can fix misfires, rough idle, poor acceleration, or a flashing check engine light. The 1.0L EcoBoost uses three coil-on-plug ignition coils mounted on top of the engine under the engine cover.

Difficulty Level: Beginner | Estimated Time: 0.5-1 hour

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⚠️ Safety & Precautions

• ⚠️ Let the engine cool completely before working near the turbocharger and cylinder head.
• ⚠️ Disconnect the negative battery cable to avoid accidental short circuits while unplugging ignition connectors.
• ⚠️ Do not pull on wiring. Press the connector tab and pull the connector body only.
• ⚠️ Replace coils one at a time if you are not replacing all three, so parts and connectors do not get mixed up.

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🔧 Required Tools

You'll need the following tools for this repair:

• 8mm socket
• 10mm socket
• 1/4-inch ratchet
• 3-inch extension
• Torque wrench inch-pound
• Plastic trim removal tool
• Needle-nose pliers
• Shop towels
• Safety glasses
• Nitrile gloves

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1-3
• Dielectric grease - Qty: 1 small tube

Dielectric grease is a non-conductive silicone grease used to seal moisture out of electrical boots.

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📋 Before You Begin

• 🅿️ Park your Focus on level ground, set the parking brake, and shift the manual transmission into neutral.
• 🔋 Open the hood and let the engine cool for at least 30 minutes if it was recently driven.
• 🔌 Use a 10mm socket to disconnect the negative battery cable, then move the cable aside so it cannot spring back to the battery post.
• 🧼 Wipe loose dirt from the top of the engine with shop towels so debris does not fall near the spark plug wells.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the Engine Cover

• Use both hands to lift the plastic engine cover straight upward.
• If it feels stuck, use a plastic trim removal tool to gently help release the rubber mounting grommets.
• Set the cover aside in a safe place.
• Lift evenly to avoid cracking plastic.

Step 2: Locate the Ignition Coils

• The ignition coils are the three small electrical units on top of the engine, each sitting above a spark plug.
• A coil-on-plug coil means the coil sits directly on the spark plug instead of using a long spark plug wire.
• Identify the coil you are replacing before unplugging anything.

Step 3: Unplug the Coil Connector

• Put on safety glasses and nitrile gloves.
• Press the locking tab on the ignition coil connector with your thumb.
• If the tab is tight, use needle-nose pliers gently on the connector body, not the wires.
• Pull the connector straight back from the coil.
• Never pull by the wires.

Step 4: Remove the Coil Retaining Bolt

• Use an 8mm socket, 3-inch extension, and 1/4-inch ratchet to remove the ignition coil retaining bolt.
• Place the bolt in a tray or safe spot so it does not fall into the engine bay.

Step 5: Remove the Old Ignition Coil

• Grip the top of the ignition coil by hand.
• Twist it slightly left and right to loosen the rubber boot from the spark plug.
• Pull the coil straight upward and out of the spark plug well.
• If it resists, keep twisting gently while pulling upward.
• Do not pry against the valve cover.

Step 6: Prepare the New Ignition Coil

• Compare the new ignition coil to the old one to make sure the connector shape and boot length match.
• Apply a very small amount of dielectric grease inside the end of the rubber boot using the tube tip.
• Do not put grease on the metal connector terminals.

Step 7: Install the New Ignition Coil

• Push the new ignition coil straight down into the spark plug well by hand.
• You should feel the boot seat onto the spark plug.
• Line up the bolt hole on the coil with the mounting hole on the engine.

Step 8: Tighten the Coil Retaining Bolt

• Start the bolt by hand first to avoid cross-threading.
• Use an 8mm socket, 3-inch extension, and torque wrench inch-pound to tighten the bolt.
• Torque to 6 Nm (53 in-lbs)
• Small bolts strip easily. Go gentle.

Step 9: Reconnect the Coil Connector

• Push the electrical connector straight onto the ignition coil until it clicks.
• Lightly tug the connector body by hand to make sure it is locked.

Step 10: Repeat for Additional Coils

• If replacing more than one coil, repeat Steps 3 through 9 for each remaining coil.
• Use the 8mm socket, 3-inch extension, 1/4-inch ratchet, and torque wrench inch-pound for each coil bolt.
• Torque each coil bolt to 6 Nm (53 in-lbs)

Step 11: Reinstall the Engine Cover

• Position the engine cover over its mounting points.
• Press down by hand until the cover seats fully into the rubber grommets.

Step 12: Reconnect the Battery

• Place the negative battery cable back onto the battery post.
• Use a 10mm socket to tighten the negative battery terminal nut snugly.
• Torque to 5 Nm (44 in-lbs)

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✅ After Repair

• ✅ Start your Focus and let it idle for 1-2 minutes.
• ✅ The engine should idle smoothly without shaking or stumbling.
• ✅ If the check engine light was on, a scan tool may be needed to clear stored misfire codes after the repair.
• ✅ Take a short test drive and accelerate gently at first to confirm the misfire is gone.
• ✅ If the check engine light flashes during the test drive, stop driving and recheck the coil connector and installation.

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💰 DIY vs Shop Cost

Shop Cost: $180-$450 (parts + labor)

DIY Cost: $35-$210 (parts only)

You Save: $145-$240 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1 hour.

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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.