🔧 Traverse - Ignition Coil Replacement

On your Traverse, each cylinder has its own ignition coil mounted on the valve covers. Replacing a bad coil restores smooth running, fixes misfires, and prevents catalytic converter damage from unburned fuel.

Difficulty Level: Intermediate | Estimated Time: 1.5-3.0 hours

Assumption: 3.6L with plastic upper intake manifold (rear coils require intake removal).

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⚠️ Safety & Precautions

• ⚠️ Work on a fully cool engine to avoid burns.
• ⚠️ Disconnect the negative battery cable to prevent accidental shorting.
• ⚠️ Keep dirt out of the intake ports; cover openings with clean rags.
• ⚠️ Do not pull on wires; always release electrical connectors by the lock tab.
• ⚠️ If the check engine light is flashing, avoid driving until repaired.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• 1/4" drive ratchet
• 3/8" drive ratchet
• 1/4" drive extension set (3" and 6")
• 3/8" drive extension set (6" and 10")
• 3/8" drive universal joint
• 8mm socket
• 10mm socket
• 13mm socket
• Flat-blade screwdriver
• Trim clip removal tool
• Small pick tool
• Torque wrench (inch-pound)
• Torque wrench (ft-lb)
• Flashlight

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1 (or Qty: 6 if replacing all)
• Ignition coil boot - Qty: 1 (or Qty: 6 if replacing all)
• Upper intake manifold gasket set - 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.
• Open the hood and let the engine cool completely.
• Use a 10mm socket to disconnect the negative battery cable and move it aside so it can’t spring back.
• Plan to replace the rear-bank coils: the upper intake manifold must come off for access.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine appearance cover

• Pull up firmly on the plastic engine cover to release it from the rubber grommets (no tools on most setups).
• Set the cover aside.

Step 2: Remove the air intake duct (to reach the intake manifold area)

• Use an 8mm socket or flat-blade screwdriver to loosen the hose clamps at the throttle body and air box.
• Unplug the intake sensor connector by lifting the lock tab with a small pick tool (a pick is a small hooked tool for releasing tabs).
• Lift the intake duct out.

Step 3: Remove the upper intake manifold (needed for rear ignition coils)

• Unplug any visible intake sensors (MAP/ETC related) by pressing the lock and pulling straight off.
• Disconnect vacuum/PCV hoses by twisting gently, then pulling off. Use a trim clip removal tool if a retaining clip is present.
• Unbolt the intake manifold fasteners using a 10mm socket with a 1/4" drive extension.
• Carefully lift the intake manifold straight up and out.
• Immediately stuff clean rags into the intake ports to keep bolts/dirt out.
• Torque on reassembly: Torque intake manifold bolts to 10 Nm (89 in-lbs)
• Tip: Take a photo before unplugging anything.

Step 4: Identify the coil(s) to replace

• You’ll see individual coils bolted to the valve covers (front bank is near the radiator; rear bank is near the firewall).
• If you’re replacing one failed coil, match its cylinder location to your diagnostic (misfire code like P0302 = cylinder 2).

Step 5: Unplug the ignition coil electrical connector

• Press the connector lock tab and pull the connector straight off the coil.
• If it’s stubborn, use a small pick tool gently on the lock tab (do not break it).

Step 6: Remove the ignition coil

• Remove the coil mounting bolt using a 10mm socket and 1/4" drive ratchet.
• Pull the coil straight up with a small twist to release the boot from the spark plug.
• Torque on reassembly: Torque ignition coil bolt to 10 Nm (89 in-lbs)

Step 7: Transfer/replace the coil boot and apply dielectric grease

• If the new coil does not include a boot, pull the rubber boot off the old coil and install it on the new coil.
• Apply a small dab of dielectric grease inside the boot lip (this helps prevent moisture and makes future removal easier).
• Tip: Only a pea-sized amount is enough.

Step 8: Install the new ignition coil

• Push the coil straight down until you feel the boot fully seat on the spark plug.
• Install the coil bolt by hand first (prevents cross-threading), then tighten using a 10mm socket.
• Torque: Torque ignition coil bolt to 10 Nm (89 in-lbs)
• Reconnect the electrical connector until it clicks.

Step 9: Reinstall the upper intake manifold

• Remove the rags from the intake ports.
• Replace the intake manifold gaskets with the new set (do not reuse flattened gaskets).
• Set the intake manifold in place carefully.
• Start all bolts by hand, then snug evenly using a 10mm socket.
• Torque: Torque intake manifold bolts to 10 Nm (89 in-lbs)
• Reconnect all vacuum hoses and electrical connectors.

Step 10: Reinstall the intake duct and engine cover

• Reinstall the intake duct and tighten clamps using an 8mm socket or flat-blade screwdriver.
• Plug the intake sensor connector back in until it clicks.
• Press the engine cover back onto its grommets.

Step 11: Reconnect the battery

• 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.
• Check for intake air leaks: listen for hissing around the intake manifold and intake duct.
• If the check engine light stays on, use a scan tool to clear codes and confirm the misfire is gone.
• Road test for 10–15 minutes, then recheck for warning lights.

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💰 DIY vs Shop Cost

Shop Cost: $300-$850 (parts + labor, depends on 1 coil vs all 6)

DIY Cost: $40-$420 (parts only)

You Save: $260-$430 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-3.0 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.