🔧 Traverse - Spark Plug Replacement

On your Traverse, the front 3 spark plugs are easy to reach, but the rear 3 sit under the intake manifold (the large plastic/aluminum “air plumbing” on top of the engine). Replacing all 6 restores smooth running, fuel economy, and helps prevent misfires.

Difficulty Level: Advanced | Estimated Time: 2.5-4.0 hours

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⚠️ Safety & Precautions

• 🧯 Work on a fully cool engine to avoid burns and damaged threads.
• 🔋 Disconnect the negative battery cable before unplugging ignition coils.
• 👓 Wear safety glasses; dirt can fall when removing the intake manifold.
• 🧼 Keep debris out of the intake ports; cover openings with clean rags immediately.
• ⚠️ Do not use anti-seize on OEM-style plated spark plugs unless the plug maker specifically requires it.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• 10mm socket
• 8mm socket
• 5/8" spark plug socket
• 3/8" drive ratchet
• 3/8" drive extension set (3", 6", 10")
• 3/8" drive swivel/universal joint
• Torque wrench (3/8" drive, 10-30 Nm range)
• Torque wrench (1/4" drive, inch-pound, 50-150 in-lb range)
• Flathead screwdriver
• Trim clip removal tool
• Needle-nose pliers
• Compressed air blow gun or shop vacuum
• Painter’s tape and marker

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs (iridium, correct OE spec) - Qty: 6
• Upper intake manifold gasket set - Qty: 1
• Throttle body gasket - Qty: 1
• Dielectric grease - Qty: 1

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📋 Before You Begin

• 🅿️ Park on level ground, shift to Park, and set the parking brake.
• 🔋 Disconnect the negative battery cable using a 10mm socket.
• 🏷️ Use painter’s tape and marker to label any hoses/connectors you unplug so they go back to the same place.
• 🧰 If you’ve never used one: a torque wrench tightens bolts to an exact spec so you don’t strip threads.
• 🧩 A swivel/universal joint is a hinged adapter that helps reach bolts at an angle.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover and intake duct

• Pull up to remove the engine cover by hand (it’s held by rubber grommets).
• Use an 8mm socket or flathead screwdriver to loosen the air duct clamps.
• Unclip/remove any intake duct retainers using a trim clip removal tool, then lift the duct off.

Step 2: Replace the front bank (radiator-side) spark plugs

• Unplug each ignition coil electrical connector (press the lock tab), then remove the coil bolt(s) using a 10mm socket.
• Lift the coil straight up and out.
• Blow/vacuum dirt from the plug well using compressed air blow gun or shop vacuum.
• Remove the spark plug using a 5/8" spark plug socket, 3/8" ratchet, and extension.
• Install the new plug by hand first using the spark plug socket and extension (no ratchet yet). Hand-threading prevents cross-threading.
• Tighten with a torque wrench (3/8"): Torque to 18 Nm (13 ft-lbs).
• Apply a small dab of dielectric grease inside the coil boot, reinstall the coil, and tighten the coil bolt(s) using a torque wrench (1/4"): Torque to 10 Nm (89 in-lb).
• Reconnect the coil connector until it clicks.

Step 3: Remove components blocking the upper intake manifold

• Disconnect the intake tube/ducting still attached to the throttle body using an 8mm socket or flathead screwdriver.
• Unplug the throttle body electrical connector and any nearby sensors/connectors you need for clearance.
• Use needle-nose pliers to release spring clamps (if equipped) and move any small vacuum/PCV hoses off the manifold.
• Label each connector/hose with painter’s tape and marker.

Step 4: Remove the upper intake manifold (rear plug access)

• Remove the upper intake manifold bolts using a 10mm socket and 3/8" ratchet.
• Carefully lift the manifold straight up and out. If it sticks, gently rock it—do not pry aggressively.
• Immediately cover the exposed intake ports with clean rags (use your gloves and rags you have on hand).
• Remove old intake manifold gaskets and install the new upper intake manifold gasket set.

Step 5: Replace the rear bank (firewall-side) spark plugs

• Unplug the rear ignition coil connectors, then remove coil bolt(s) using a 10mm socket.
• Remove coils, then blow/vacuum the plug wells using compressed air blow gun or shop vacuum.
• Use a 5/8" spark plug socket, extension, and 3/8" swivel/universal joint to remove each rear plug.
• Install new plugs by hand first with the spark plug socket and extension.
• Tighten with a torque wrench (3/8"): Torque to 18 Nm (13 ft-lbs).
• Add a small dab of dielectric grease to each coil boot, reinstall coils, and tighten coil bolt(s) with a torque wrench (1/4"): Torque to 10 Nm (89 in-lb).
• Reconnect all coil connectors.

Step 6: Reinstall the upper intake manifold and throttle body connections

• Remove the rags from the intake ports.
• Set the upper intake manifold back into place, ensuring the gaskets stay seated.
• Install manifold bolts finger-tight first, then snug evenly using a 10mm socket.
• Tighten manifold bolts with a torque wrench (3/8"): Torque to 10 Nm (89 in-lb).
• If the throttle body was separated, install a new throttle body gasket and tighten fasteners using an 8mm socket, then Torque to 10 Nm (89 in-lb) with the torque wrench (3/8").
• Reconnect every hose and electrical connector you labeled.

Step 7: Reinstall intake ducting and engine cover

• Reinstall the intake duct and tighten clamps using an 8mm socket or flathead screwdriver.
• Reinstall any clips using a trim clip removal tool (as needed).
• Press the engine cover back onto its grommets by hand.
• Reconnect the negative battery cable using a 10mm socket.

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✅ After Repair

• 🔎 Start the engine and let it idle for 1–2 minutes; it should run smooth with no shaking.
• 🧠 If the check engine light was on before, scan and clear codes after verifying the repair.
• 🕵️ Listen for hissing (vacuum leak) around the intake; recheck hose connections if you hear it.
• 🚗 Test drive 10–15 minutes, then recheck for warning lights.

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💰 DIY vs Shop Cost

Shop Cost: $450-$850 (parts + labor)

DIY Cost: $90-$220 (parts only)

You Save: $360-$630 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2.5-4.0 hours.

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🎯 Ready to get started?

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