🔧 Traverse - Spark Plug Replacement

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

Difficulty Level: Intermediate | Estimated Time: 2.5-4.5 hours

---

⚠️ Safety & Precautions

• ⚠️ Work on a cold engine to avoid burns and damaged threads.
• ⚠️ Disconnect the negative battery cable before unplugging the electronic throttle body and ignition coils.
• ⚠️ Keep dirt out of the intake ports; cover openings with clean shop towels.
• ⚠️ Do not use anti-seize on these spark plugs; the threads are coated from the factory.
• ⚠️ Use a torque wrench; over-tightening can damage the cylinder head.

---

🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• 10mm socket
• 8mm socket
• Ratchet (3/8" drive)
• Socket extension set (3", 6", 10")
• Universal swivel joint (3/8" drive)
• 5/8" spark plug socket (rubber insert)
• Torque wrench (10–30 Nm range)
• Flathead screwdriver
• Trim clip tool
• Needle-nose pliers
• Compressed air blow gun
• Shop towels
• Telescoping magnet pickup tool
• Dielectric grease

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

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

---

📋 Before You Begin

• 🧰 Park on level ground, shift to Park, and set the parking brake.
• 🧰 Open the hood and let the engine fully cool.
• 🧰 Use a 10mm socket to disconnect the negative battery cable and isolate it so it can’t spring back.
• 🧰 Blow off dirt around the ignition coils and intake area using compressed air to keep debris out of the engine.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover

• Pull up firmly on the engine cover to release the retaining grommets, then lift it off by hand.
• Rock it gently if it feels stuck.

Step 2: Remove the air intake duct

• Use an 8mm socket (or flathead screwdriver if your clamp is slotted) to loosen the intake clamps.
• Disconnect any small breather hose(s) using needle-nose pliers.
• Unplug the MAF sensor connector using your fingers (press the tab), then remove the duct.

Step 3: Remove the front-bank ignition coils (front 3 cylinders)

• Unplug each coil electrical connector by pressing the lock tab and pulling straight back.
• Use a 10mm socket to remove the coil bolts.
• Twist each coil boot slightly, then pull the coil upward to remove it.
• Torque to 10 Nm (89 in-lbs) when reinstalling coil bolts.
• Coil boot = the rubber “spark plug socket” on the coil.

Step 4: Remove the front 3 spark plugs

• Blow compressed air down each spark plug well to remove dirt.
• Use a 5/8" spark plug socket, extension, and ratchet to loosen and remove each plug.
• Install the new spark plugs by hand first using the spark plug socket and extension (no ratchet) to avoid cross-threading.
• Use a torque wrench to tighten each spark plug: Torque to 18 Nm (13 ft-lbs).
• Apply a small dab of dielectric grease inside each coil boot, then reinstall coils.

Step 5: Remove the throttle body connections

• Unplug the throttle body electrical connector by pressing the tab and pulling straight back.
• If your throttle body has coolant hoses, use needle-nose pliers to move the spring clamps back, then carefully remove hoses (catch any drips with shop towels).
• Use a 10mm socket to remove the throttle body mounting bolts if it must be separated from the intake.
• Torque to 10 Nm (89 in-lbs) when reinstalling throttle body bolts.

Step 6: Remove the upper intake manifold (to access the rear 3 plugs)

• Unplug sensors on the intake (commonly MAP), and disconnect the EVAP purge line using the release tabs (use a trim clip tool carefully if needed).
• Use a 10mm socket to remove the upper intake manifold bolts.
• Lift the manifold straight up and off; use shop towels to immediately cover the intake ports.
• Torque to 25 Nm (18 ft-lbs) when reinstalling the upper intake manifold bolts.
• Intake ports = the open holes into the engine.

Step 7: Replace the rear-bank spark plugs (rear 3 cylinders)

• Unplug the 3 rear ignition coil connectors.
• Use a 10mm socket to remove the rear coil bolts, then remove the coils.
• Blow out the spark plug wells with compressed air.
• Use the 5/8" spark plug socket, extensions, and a swivel joint to remove the plugs.
• Install new plugs by hand first, then tighten: Torque to 18 Nm (13 ft-lbs).
• Reinstall coils and tighten coil bolts: Torque to 10 Nm (89 in-lbs).

Step 8: Reassemble intake and air ducting

• Remove the shop towels from the intake ports.
• Install new upper intake manifold gaskets, then set the manifold in place.
• Hand-start all intake bolts, then tighten evenly: Torque to 25 Nm (18 ft-lbs).
• Reinstall the throttle body with a new gasket if removed: Torque to 10 Nm (89 in-lbs).
• Reconnect EVAP line(s), sensor connectors, and any hoses.
• Reinstall the air intake duct and tighten clamps using an 8mm socket.
• Plug the MAF sensor back in.

Step 9: Reconnect battery and reinstall engine cover

• Use a 10mm socket to reconnect the negative battery cable snugly.
• Press the engine cover back onto its grommets by hand.

---

✅ After Repair

• 🧪 Start the engine and let it idle for 2–3 minutes; it may run slightly rough for a few seconds while it relearns idle.
• 🧪 Check for warning lights and listen for vacuum leaks (a hissing sound) around the intake.
• 🧪 Take a short test drive and recheck for any fuel/vacuum smells under the hood.
• 🧪 If you had a misfire check-engine light before, use a scan tool to clear codes and confirm the misfire is gone.

---

💰 DIY vs Shop Cost

Shop Cost: $350-$650 (parts + labor)

DIY Cost: $70-$180 (parts only)

You Save: $280-$470 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.

---

🎯 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.