🔧 Accord - Spark Plug Replacement

Replacing the spark plugs on your Accord helps the engine start smoothly, run efficiently, and avoid misfires. On the hybrid 2.0L engine, the plugs sit under the ignition coils on top of the engine, so the job is straightforward but needs care around the high-voltage hybrid system.

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

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⚠️ Safety & Precautions

• ⚠️ Your Accord is a hybrid. Do not touch orange high-voltage cables or hybrid system components.
• ⚠️ Work only with the vehicle OFF, key fob away from the car, and the engine completely cool.
• ⚠️ Disconnect the 12V battery negative terminal before unplugging ignition coils.
• ⚠️ Never remove spark plugs from a hot aluminum cylinder head; the threads can be damaged.
• ⚠️ Do not apply anti-seize to modern coated spark plug threads unless the plug maker specifically instructs it.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 3/8-inch ratchet
• 3/8-inch torque wrench
• 5/8-inch spark plug socket
• 6-inch 3/8-inch extension
• Plastic trim removal tool
• Compressed air nozzle
• Spark plug gap gauge
• Needle-nose pliers
• Dielectric grease
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Iridium spark plugs - Qty: 4

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📋 Before You Begin

• Park your Accord on level ground and shift to Park.
• Set the parking brake.
• Open the hood and let the engine cool fully.
• Keep the key fob at least 15 feet away so the hybrid system cannot wake up unexpectedly.
• Disconnect the 12V battery negative terminal using a 10mm socket. The 12V battery is in the trunk area on this Accord.
• A spark plug socket has a rubber insert or magnet that holds the plug so it does not fall into the plug well.
• A torque wrench tightens bolts or plugs to an exact tightness so parts are not damaged.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the Engine Cover

• Use your hands to gently lift the plastic engine cover upward from its rubber mounts.
• If it feels stuck, use a plastic trim removal tool to gently help lift one corner.
• Set the cover aside where it will not get scratched.
• Lift straight up, not sideways.

Step 2: Clean Around the Ignition Coils

• Put on safety glasses before using compressed air.
• Use a compressed air nozzle to blow dust and grit away from the top of the engine.
• Pay close attention around each ignition coil. The ignition coil is the small electrical part that sits directly above each spark plug.
• This prevents dirt from falling into the engine when the spark plugs are removed.

Step 3: Disconnect the Ignition Coil Connectors

• Use your fingers to press the release tab on the first ignition coil connector.
• Pull the connector straight back. Do not pull on the wires.
• If the connector is tight, use needle-nose pliers gently on the connector body only.
• Repeat for all 4 ignition coils.
• Take a photo before unplugging.

Step 4: Remove the Ignition Coils

• Use a 10mm socket and 3/8-inch ratchet to remove the hold-down bolt from the first ignition coil.
• Twist the ignition coil slightly by hand, then pull it straight up.
• Set each coil in order so it goes back into the same cylinder.
• Repeat for all 4 ignition coils.
• On reinstallation, tighten each ignition coil bolt to Torque to 12 Nm (9 ft-lbs).

Step 5: Blow Out the Spark Plug Wells

• Use a compressed air nozzle to blow into each spark plug well before removing the plugs.
• The spark plug well is the deep tube where the spark plug sits.
• This step is important because dirt can fall into the cylinder if skipped.

Step 6: Remove the Old Spark Plugs

• Attach the 5/8-inch spark plug socket to the 6-inch 3/8-inch extension and 3/8-inch ratchet.
• Lower the socket straight down into the first spark plug well.
• Turn counterclockwise slowly to loosen the spark plug.
• Once loose, spin it out by hand using the extension.
• Lift the plug out carefully using the spark plug socket.
• Repeat for all 4 spark plugs.
• Keep the socket perfectly straight.

Step 7: Check the New Spark Plugs

• Use a spark plug gap gauge to verify the new plug gap is correct.
• For your Accord, use the plug gap specified for the exact replacement iridium plugs supplied for this engine.
• Do not force-adjust fine-wire iridium plugs unless the plug manufacturer allows it. The small center tip can break.
• Do not put anti-seize on the threads unless the spark plug manufacturer specifically says to use it.

Step 8: Install the New Spark Plugs by Hand

• Place one new iridium spark plug into the 5/8-inch spark plug socket.
• Lower it into the spark plug well using the 6-inch 3/8-inch extension.
• Turn clockwise by hand only for several turns.
• If it does not turn smoothly, stop and restart. This prevents cross-threading, which means damaging the aluminum threads in the cylinder head.
• Repeat for all 4 spark plugs.

Step 9: Torque the New Spark Plugs

• Attach the 5/8-inch spark plug socket and 6-inch 3/8-inch extension to the 3/8-inch torque wrench.
• Tighten each spark plug to Torque to 18 Nm (13 ft-lbs).
• Do not over-tighten. The cylinder head is aluminum and can be damaged.
• Click once, then stop.

Step 10: Reinstall the Ignition Coils

• Apply a small amount of dielectric grease inside the rubber boot of each ignition coil.
• Dielectric grease helps seal out moisture but does not go on the metal plug terminal.
• Push each ignition coil straight down onto its spark plug until seated.
• Use a 10mm socket and 3/8-inch torque wrench to tighten each ignition coil bolt to Torque to 12 Nm (9 ft-lbs).

Step 11: Reconnect the Coil Connectors

• Push each ignition coil connector back on by hand until it clicks.
• Lightly tug each connector to make sure it is locked.
• Use needle-nose pliers only if a connector needs gentle positioning.

Step 12: Reinstall the Engine Cover and Battery Cable

• Line up the engine cover with the rubber mounts.
• Press down by hand until it snaps into place.
• Reconnect the 12V battery negative terminal using a 10mm socket.
• Tighten the battery terminal snugly. Do not overtighten.

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✅ After Repair

• Start your Accord and let it idle for a few minutes.
• The engine may take a moment to start because the hybrid system decides when to run the gasoline engine.
• Check that there are no warning lights or rough running.
• If the idle feels rough, turn the vehicle OFF and recheck that all 4 coil connectors are fully clicked in.
• Take a short test drive and listen for smooth acceleration.
• Reset the clock and any lost vehicle settings if the 12V battery disconnect cleared them.

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💰 DIY vs Shop Cost

Shop Cost: $220-$420 (parts + labor)

DIY Cost: $55-$130 (parts only)

You Save: $165-$290 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1-2 hours.

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🎯 Ready to get started?

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