🔧 Civic - Ignition Coil Replacement

Your Civic uses one ignition coil per cylinder (coil-on-plug). Replacing a bad coil restores smooth running and fixes misfires, rough idle, and flashing check-engine light issues.

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

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⚠️ Safety & Precautions

• ⚠️ Let the engine cool fully before working near the exhaust and cylinder head.
• ⚠️ Keep tools and hands away from the radiator fan area (it can turn on unexpectedly).
• ⚠️ If the check-engine light is flashing, avoid driving much (active misfire can damage the catalytic converter).
• ⚠️ Battery disconnect is not required, but disconnecting the negative terminal helps prevent accidental shorts.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" drive ratchet
• 6" extension (1/4" drive)
• Torque wrench (inch-pound or small Nm range)
• Trim clip remover
• Flathead screwdriver
• 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, engine off, and set the parking brake.
• Open the hood and remove any loose items near the engine bay.
• If you choose to disconnect the battery: use a 10mm socket to remove the negative terminal and keep it from touching the post.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover (if equipped)

• Use a 10mm socket and 1/4" drive ratchet to remove the engine cover fasteners.
• Lift the cover straight up and set it aside.

Step 2: Locate the ignition coils

• The coils sit on top of the engine valve cover, one per cylinder, in a row.
• Work one coil at a time to avoid mix-ups.

Step 3: Unplug the coil electrical connector

• Press the connector lock tab and pull the connector off the coil by hand.
• If the tab is stubborn, use a flathead screwdriver gently to help lift the lock tab (do not pry hard).

Step 4: Remove the coil hold-down bolt

• Use a 10mm socket, 6" extension (1/4" drive), and 1/4" drive ratchet to remove the bolt holding the coil down.
• Set the bolt aside where it can’t fall into the engine bay.

Step 5: Pull the coil out

• Twist the coil gently left-right by hand, then pull straight up to remove it.
• If it’s stuck, use a trim clip remover to gently assist from the base area (light pressure only).

Step 6: Prep and install the new coil

• Apply a very thin smear of dielectric grease inside the rubber boot (dielectric grease is a non-conductive grease that helps prevent moisture and makes future removal easier).
• Push the new coil straight down onto the spark plug until it seats fully.

Step 7: Reinstall the hold-down bolt and torque it

• Start the bolt by hand to avoid cross-threading.
• Use a 10mm socket and torque wrench (inch-pound or small Nm range) to tighten the bolt.
• Torque to 10 Nm (7 ft-lbs)

Step 8: Reconnect the electrical connector

• Push the connector on until it clicks into place.
• Give it a light tug to confirm it’s locked.

Step 9: Repeat for any other coils you’re replacing

• Use the same process for cylinders 2-4 if replacing more than one coil.

Step 10: Reinstall the engine cover

• Set the cover back in place.
• Use the 10mm socket and 1/4" drive ratchet to snug the fasteners (do not over-tighten).

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✅ After Repair

• If you disconnected the battery, reconnect the negative terminal using the 10mm socket.
• Start the engine and let it idle for 1-2 minutes. It should run smooth with no shaking.
• Take a short test drive and verify no flashing check-engine light.
• If the check-engine light stays on, scan for codes with an OBD2 scan tool (specialty) (an OBD2 scan tool reads trouble codes from the car’s computer).

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💰 DIY vs Shop Cost

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

DIY Cost: $45-$260 (parts only)

You Save: $135-$190 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.