🔧 HR-V - Spark Plug Replacement

Your HR-V uses coil-on-plug ignition (one ignition coil sitting on each spark plug). Replacing the plugs restores smooth starts, fuel economy, and prevents misfires as the plugs wear.

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

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⚠️ Safety & Precautions

• 🛑 Work on a fully cool engine to avoid burns and damaged threads.
• 🛑 Keep dirt out of the plug holes; debris can damage the engine.
• 🛑 Do not over-tighten spark plugs; the cylinder head is aluminum.
• 🛑 Battery disconnect is not required, but keep ignition OFF and the key/fob away from the vehicle while working.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• 10mm socket
• 3/8" drive ratchet
• 3/8" drive extension set (3" and 6")
• 5/8" (16mm) thin-wall spark plug socket
• Torque wrench (3/8" drive, 10-30 Nm range)
• Compressed air blow gun
• Small flat trim tool

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Iridium spark plugs (OEM-style for HR-V 1.8L) - Qty: 4
• Dielectric grease (silicone) - Qty: 1

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📋 Before You Begin

• 🅿️ Park on level ground, shift to Park, and set the parking brake.
• 🧊 Let the engine cool completely (at least 1 hour after driving).
• 🧹 Have compressed air ready to blow out dirt around each ignition coil before removal.
• 🧠 A “thin-wall spark plug socket” is a socket made to fit deep, narrow plug wells without getting stuck.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover (if equipped)

• Use a small flat trim tool to gently pop up any cover fasteners (if present).
• Lift the cover off by hand and set it aside.

Step 2: Locate and unplug the ignition coils

• Find the four ignition coils on top of the engine (one per cylinder).
• Press the tab and unplug the coil electrical connector by hand. If it’s tight, use a small flat trim tool gently. Don’t pull on the wires.

Step 3: Remove the ignition coils

• Use a 10mm socket with a 3/8" drive ratchet to remove the coil hold-down bolt.
• Twist the coil slightly, then pull it straight up and out by hand.
• Repeat for all four coils (do one cylinder at a time to avoid mixing parts).

Step 4: Blow out the spark plug wells

• Use a compressed air blow gun to blow out dirt from each spark plug tube before removing the plug.

Step 5: Remove the old spark plug

• Install the 5/8" (16mm) thin-wall spark plug socket onto a 3/8" drive extension (6") and 3/8" drive ratchet.
• Lower the socket straight down onto the spark plug and loosen it counterclockwise.
• Once loose, spin it out and lift it out with the socket.

Step 6: Install the new spark plug

• Start the new plug by hand first: place the plug into the socket and carefully thread it in using only the extension (no ratchet at first). This helps prevent cross-threading.
• Once it seats, use a torque wrench (3/8" drive) and tighten to Torque to 18 Nm (13 ft-lbs).
• Do not use anti-seize on Honda iridium plugs.

Step 7: Reinstall the ignition coil

• Apply a tiny dab of dielectric grease (silicone) inside the coil boot (the rubber sleeve) with a fingertip. This helps prevent sticking and moisture.
• Push the coil straight down until it fully seats on the plug.
• Install the coil bolt using a 10mm socket, then tighten with a torque wrench to Torque to 12 Nm (9 ft-lbs).
• Plug the electrical connector back in until it clicks.

Step 8: Repeat for the remaining cylinders

• Repeat Steps 4–7 for the other three spark plugs.

Step 9: Reinstall the engine cover

• Reinstall the cover by hand and snap/push fasteners back in place (if equipped).

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✅ After Repair

• 🔍 Start the engine and let it idle for 30–60 seconds. It should run smooth with no shaking.
• 🔍 If the check engine light comes on or it runs rough, re-check that every coil connector is fully clicked in and each coil is seated.
• 🧪 Take a short test drive and verify normal acceleration with no hesitation.

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💰 DIY vs Shop Cost

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

DIY Cost: $45-$110 (parts only)

You Save: $140-$405 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.0-1.5 hours.

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🎯 Ready to get started?

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