🔧 Spark Plugs - Replacement

On your CX-5, the spark plugs sit under the ignition coils on top of the engine. This job is straightforward, but it must be done on a cold engine so you do not damage the aluminum cylinder head or burn yourself.

Difficulty Level: Beginner | Estimated Time: 1.5-2.5 hours

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⚠️ Safety & Precautions

• Work only on a completely cold engine.
• Keep dirt out of the spark plug wells. Any debris that falls in can damage the engine.
• Disconnect the negative battery cable if you want extra safety around the ignition system.
• Do not use anti-seize on the new plugs unless the plug maker specifically calls for it.
• Hand-start every spark plug to avoid cross-threading the cylinder head.
• Small mistakes here can get expensive.

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🔧 Required Tools

You'll need the following tools for this repair:

• 8mm socket
• 10mm socket
• 3/8-inch ratchet
• 6-inch extension
• Spark plug socket, 14mm (5/8-inch) with rubber insert
• Torque wrench
• Flat-blade trim tool
• Needle-nose pliers
• Compressed air or air blower
• Gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs - Qty: 4

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📋 Before You Begin

• Park on level ground and set the parking brake.
• Let the engine cool fully before starting.
• If you disconnect the battery, save radio presets first.
• Keep the new plugs in their boxes until installation.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover

• Pull up on the engine cover to release it from the mounting grommets.
• If it feels stuck, use a flat-blade trim tool gently under one edge.

Step 2: Move the intake duct if needed

• If the front of the engine is crowded, loosen the intake duct clamps with an 8mm socket.
• Lift the duct out of the way for better access to the coil packs.

Step 3: Disconnect the ignition coil connectors

• Press the locking tab on each connector and unplug it by hand.
• If a connector is tight, use needle-nose pliers lightly on the release tab only.

Step 4: Remove the ignition coils

• Use a 10mm socket and 3/8-inch ratchet to remove each coil hold-down bolt.
• Twist each coil slightly, then pull it straight up.
• Do not yank on the wiring.

Step 5: Clean the spark plug wells

• Use compressed air or an air blower to clear dirt from each well.
• This keeps debris from falling into the cylinder when the plug comes out.

Step 6: Remove the old spark plugs

• Use the spark plug socket, 6-inch extension, and 3/8-inch ratchet to loosen each plug.
• Turn counterclockwise and remove one plug at a time.
• Check that the old plug came out cleanly and nothing is left behind.

Step 7: Install the new spark plugs

• Start each new plug by hand using the spark plug socket and extension only.
• If a plug does not thread in easily, stop and back it out.
• Tighten each plug with a torque wrench to 18 Nm (13 ft-lbs).
• Hand-start first, always.

Step 8: Reinstall the ignition coils

• Push each coil straight down onto its spark plug until fully seated.
• Install the coil bolts with a 10mm socket.
• Torque to 8 Nm (71 in-lbs).
• Reconnect each electrical connector until it clicks.

Step 9: Reinstall intake parts and engine cover

• Reinstall any intake duct pieces you removed using the 8mm socket.
• Press the engine cover back onto its mounts by hand.

Step 10: Start and verify

• Reconnect the battery if you disconnected it.
• Start the engine and let it idle.
• Listen for misfires, rough idle, or warning lights.

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✅ After Repair

• Let the engine idle for a few minutes and make sure it runs smoothly.
• Take a short test drive and confirm normal acceleration.
• If the check engine light is on, scan for misfire codes.
• Recheck that all coil connectors and bolts are secure.

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💰 DIY vs Shop Cost

Shop Cost: $180-$320 (parts + labor)

DIY Cost: $40-$90 (parts only)

You Save: $140-$230 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-2.0 hours.

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🎯 Ready to get started?

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