🔧 Edge - Spark Plug Replacement

On your Edge, the spark plugs fire the air/fuel mix in each cylinder. Worn plugs can cause rough idle, misfires, poor fuel economy, and hard starts. This job is straightforward because the plugs are accessed from the top of the engine.

Difficulty Level: Intermediate | Estimated Time: 1.0-2.0 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a fully cool engine to avoid burns and stripped threads.
• ⚠️ Keep dirt out of the spark plug holes; grit can damage the engine.
• ⚠️ Disconnect the negative battery cable if you’re nervous about unplugging electrical connectors.
• ⚠️ Do not over-tighten spark plugs; the cylinder head is aluminum.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm wrench
• 8mm socket
• 1/4" drive ratchet
• 6" extension (1/4" drive)
• 5/8" spark plug socket
• 3/8" drive ratchet
• 6" extension (3/8" drive)
• Torque wrench (inch-pound)
• Torque wrench (foot-pound)
• Trim clip removal tool
• Small flathead screwdriver
• Compressed air blow gun (specialty)
• Feeler gauge set
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs (OEM-equivalent, iridium/platinum as specified) - Qty: 4
• Dielectric grease - Qty: 1

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📋 Before You Begin

• Park on level ground and let the engine cool completely.
• Open the hood and remove any loose items around the engine bay.
• If disconnecting the battery: use a 10mm wrench to remove the negative battery cable and keep it from touching the terminal.
• Take a quick photo before unplugging connectors.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine appearance cover

• Grip the cover and pull straight up to release the rubber grommets.
• If your cover uses clips, use a trim clip removal tool to lift them without breaking.

Step 2: Unplug the ignition coils

• Each cylinder has an ignition coil (a “coil-on-plug” unit, meaning the coil sits directly on the plug).
• Use a small flathead screwdriver to gently lift the connector lock tab if needed, then unplug the connector.

Step 3: Remove the ignition coils

• Use an 8mm socket with a 1/4" drive ratchet and 6" extension (1/4" drive) to remove the coil hold-down bolt.
• Twist the coil slightly and pull straight up to remove it.
• Keep coils in order—same cylinder if reusing.

Step 4: Clean around the spark plug wells

• Put on safety glasses.
• Use a compressed air blow gun (specialty) to blow dirt out of each spark plug well before removing the plug.

Step 5: Remove the old spark plugs

• Use a 5/8" spark plug socket with a 3/8" drive ratchet and 6" extension (3/8" drive) to loosen and remove each plug.
• Turn counterclockwise steadily. If it feels stuck, stop and apply gentle back-and-forth to avoid thread damage.

Step 6: Check the new plug gap (do not force-adjust fine-wire plugs)

• “Gap” is the small space between the center and ground electrode where the spark jumps.
• Use a feeler gauge set to verify the gap matches the plug maker’s spec for your application.
• If the plugs are fine-wire iridium, do not pry on the electrode; replace any plug that’s out of spec.

Step 7: Install the new spark plugs

• Start each plug by hand using the 5/8" spark plug socket and extension only (no ratchet at first) so it threads in smoothly.
• Once seated, torque each spark plug with a torque wrench (foot-pound): Torque to 15 Nm (11 ft-lbs).
• Hand-threading prevents cross-threading.

Step 8: Reinstall the ignition coils

• Apply a tiny smear of dielectric grease inside each coil boot (it helps prevent moisture and makes future removal easier).
• Push the coil straight down onto the spark plug until fully seated.
• Install the coil bolt using an 8mm socket and 1/4" drive ratchet, then torque with a torque wrench (inch-pound): Torque to 5 Nm (44 in-lbs).
• Plug in the electrical connector until it clicks/locks.

Step 9: Reinstall the engine cover and reconnect battery (if disconnected)

• Press the engine cover back onto its mounting points until it snaps into place.
• If you disconnected the battery, reconnect the negative cable using a 10mm wrench and tighten securely.

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✅ After Repair

• Start the engine and let it idle for 1-2 minutes. It should run smooth with no shaking.
• Listen for any ticking/hissing that could indicate a loose coil or connector.
• If the check engine light is on or it runs rough, re-check every coil connector is fully latched.

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💰 DIY vs Shop Cost

Shop Cost: $250-$450 (parts + labor)

DIY Cost: $40-$120 (parts only)

You Save: $130-$410 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.0-2.0 hours.

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🎯 Ready to get started?

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