🔧 Odyssey - Spark Plug Replacement

Changing the spark plugs on your Odyssey helps keep the engine starting smoothly, idling cleanly, and accelerating without misfires. The V6 engine has 6 spark plugs total: 3 in the front bank and 3 in the rear bank near the firewall.

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

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⚠️ Safety & Precautions

• ⚠️ Work only on a cold engine. Hot aluminum cylinder head threads are easier to damage.
• ⚠️ Disconnect the negative battery cable before unplugging ignition coils.
• ⚠️ Keep dirt out of the spark plug holes. Anything dropped inside can damage the engine.
• ⚠️ Replace one plug at a time so parts do not get mixed up.
• ⚠️ Do not over-tighten spark plugs. The cylinder heads are aluminum.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 10mm wrench
• 3/8-inch ratchet
• 3/8-inch torque wrench
• 5/8-inch spark plug socket
• 3-inch 3/8-inch drive extension
• 6-inch 3/8-inch drive extension
• 3/8-inch universal joint socket adapter
• Needle-nose pliers
• Compressed air blower nozzle
• Spark plug gap gauge
• Fender cover
• Safety glasses
• Nitrile gloves

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Iridium spark plugs - Qty: 6
• Upper intake plenum gasket set - Qty: 1
• Throttle body gasket - Qty: 1
• Dielectric grease - Qty: 1 packet

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📋 Before You Begin

• 🅿️ Park your Odyssey on level ground, shift to Park, and set the parking brake.
• ❄️ Let the engine cool fully before removing any spark plugs.
• 🔋 Use a 10mm wrench to disconnect the negative battery cable.
• 📸 Take photos of hoses and connectors before removing the upper intake plenum.
• 📏 Check each new spark plug with a spark plug gap gauge. The correct gap is 0.044 inch.
• ℹ️ A spark plug socket has a rubber insert or magnet that holds the plug so it does not fall.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the Engine Cover

• Use your hands to pull the plastic engine cover straight upward.
• Set the cover aside safely.
• Pull straight up gently.

Step 2: Remove the Intake Air Tube

• Use a 10mm socket and 3/8-inch ratchet to loosen the clamp at the throttle body.
• Use the 10mm socket and 3/8-inch ratchet to loosen the clamp at the air filter housing.
• Use needle-nose pliers to release any small hose clamps attached to the intake tube.
• Remove the intake tube by hand and set it aside.

Step 3: Remove the Upper Intake Plenum

• The upper intake plenum is the large aluminum air chamber on top of the engine.
• Use a 10mm socket, 6-inch extension, and 3/8-inch ratchet to remove the plenum bolts.
• Unplug any electrical connectors by pressing the connector tabs by hand.
• Use needle-nose pliers to release small vacuum hose clamps if needed.
• Lift the plenum straight up by hand.
• Remove the old upper intake plenum gasket and throttle body gasket by hand.
• Cover the open intake ports with a clean towel.
• Do not drop anything inside.

Step 4: Clean the Front Spark Plug Area

• Use a compressed air blower nozzle to blow dirt away from the front ignition coils.
• An ignition coil is the small electrical part mounted above each spark plug.
• Wear safety glasses while using compressed air.

Step 5: Remove One Front Ignition Coil

• Press the electrical connector tab by hand and unplug the first front ignition coil.
• Use a 10mm socket and 3/8-inch ratchet to remove the ignition coil bolt.
• Twist the ignition coil gently by hand, then pull it straight up.

Step 6: Remove One Front Spark Plug

• Use a compressed air blower nozzle to clean inside the spark plug well.
• A spark plug well is the deep tube where the spark plug sits.
• Use a 5/8-inch spark plug socket, 6-inch extension, and 3/8-inch ratchet to turn the spark plug counterclockwise.
• Remove the old spark plug carefully.
• If stuck, stop and go slowly.

Step 7: Install One New Front Spark Plug

• Use a spark plug gap gauge to confirm the gap is 0.044 inch.
• Place the new spark plug into the 5/8-inch spark plug socket.
• Use the 6-inch extension by hand to start the new spark plug clockwise.
• Thread it in by hand until it seats. If it feels tight immediately, remove it and restart.
• Use a 3/8-inch torque wrench and 5/8-inch spark plug socket to tighten to Torque to 18 Nm (13 ft-lbs).

Step 8: Reinstall That Ignition Coil

• Apply a small amount of dielectric grease inside the rubber coil boot.
• Dielectric grease helps keep moisture out of electrical boots.
• Push the ignition coil straight down by hand until seated.
• Use a 10mm socket and 3/8-inch torque wrench to tighten the coil bolt to Torque to 12 Nm (9 ft-lbs).
• Reconnect the electrical connector by hand until it clicks.

Step 9: Repeat for the Other Two Front Spark Plugs

• Use the 10mm socket, 5/8-inch spark plug socket, extensions, ratchet, and torque wrench.
• Replace one plug completely before moving to the next one.
• Tighten each spark plug to Torque to 18 Nm (13 ft-lbs).
• Tighten each ignition coil bolt to Torque to 12 Nm (9 ft-lbs).

Step 10: Replace the Rear Spark Plugs

• Use a compressed air blower nozzle to clean around the rear ignition coils.
• Unplug one rear ignition coil by pressing the connector tab by hand.
• Use a 10mm socket, 3-inch extension, and 3/8-inch ratchet to remove the coil bolt.
• Pull the ignition coil straight up by hand.
• Use a 5/8-inch spark plug socket, 6-inch extension, 3/8-inch universal joint socket adapter, and 3/8-inch ratchet to remove the spark plug.
• A universal joint adapter lets the socket bend slightly in tight spaces.
• Install the new spark plug by hand using the 5/8-inch spark plug socket and extension.
• Use a 3/8-inch torque wrench to tighten the spark plug to Torque to 18 Nm (13 ft-lbs).
• Apply dielectric grease inside the coil boot.
• Reinstall the coil and tighten the bolt with a 10mm socket and torque wrench to Torque to 12 Nm (9 ft-lbs).
• Reconnect the coil connector by hand until it clicks.
• Repeat for the remaining two rear spark plugs.

Step 11: Reinstall the Upper Intake Plenum

• Remove the clean towel from the intake ports by hand.
• Install the new upper intake plenum gasket by hand.
• Install the new throttle body gasket by hand.
• Place the plenum back onto the engine.
• Start all bolts by hand first.
• Use a 10mm socket, 6-inch extension, and 3/8-inch torque wrench to tighten the plenum bolts evenly to Torque to 22 Nm (16 ft-lbs).
• Reconnect all hoses and electrical connectors by hand.
• Hand-start bolts to avoid damage.

Step 12: Reinstall the Intake Air Tube

• Install the intake tube by hand between the throttle body and air filter housing.
• Use a 10mm socket and 3/8-inch ratchet to tighten both clamps snugly.
• Use needle-nose pliers to reconnect any small hose clamps.

Step 13: Reconnect the Battery and Finish Up

• Use a 10mm wrench to reconnect the negative battery cable.
• Use your hands to push the engine cover back into place.

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✅ After Repair

• ✅ Start your Odyssey and let it idle for 2-3 minutes.
• ✅ Listen for a smooth idle and no hissing sounds near the intake plenum.
• ✅ If the engine shakes or the check engine light flashes, shut it off and recheck coil connectors.
• ✅ Take a short test drive after the idle sounds normal.
• ✅ Recheck the intake tube clamps after the test drive.

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💰 DIY vs Shop Cost

Shop Cost: $450-$750 (parts + labor)

DIY Cost: $90-$180 (parts only)

You Save: $270-$660 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-2.5 hours.

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🎯 Ready to get started?

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