🔧 TITAN XD - Spark Plug Replacement

On your TITAN XD, spark plugs fire the air/fuel mix in each cylinder. Worn plugs can cause rough idle, misfires, slow starts, and poor fuel economy. This job involves removing the ignition coils and (on this V8) typically lifting off the upper intake to reach the rear plugs.

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

Assumption: 5.6L V8 requires upper intake removal.

---

⚠️ Safety & Precautions

• ⚠️ Work on a fully cool engine to avoid burns.
• ⚠️ Disconnect the negative battery cable to prevent accidental shorts.
• ⚠️ Keep dirt out of the intake—cover openings with clean rags.
• ⚠️ Do not use anti-seize on modern plated spark plugs unless the plug maker specifically requires it.
• ⚠️ Use only a torque wrench—overtightening can damage aluminum cylinder head threads.

---

🔧 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
• 3/8" drive ratchet
• 3/8" drive extension set (3", 6", 10")
• 3/8" drive universal joint
• 10mm socket
• 12mm socket
• 8mm socket
• Flat-blade screwdriver
• Pliers
• Spark plug socket 14mm thin-wall (magnetic or rubber insert)
• Torque wrench 3/8" drive (10–40 ft-lbs range)
• Torque wrench 1/4" drive (inch-lb range)
• Feeler gauge set (inch/mm)
• Compressed air blow gun
• Trim clip removal tool
• Pickup magnet tool
• Shop light

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs (OEM-type for 5.6L) - Qty: 8
• Upper intake manifold gasket set - Qty: 1
• Throttle body gasket - Qty: 1
• Dielectric grease - Qty: 1

---

📋 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 isolate it so it can’t spring back.
• Label any hoses/connectors you remove with masking tape so they go back to the same place.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove engine cover and intake duct

• Remove the engine cover (pull up if it’s on rubber grommets, or use a 10mm socket if bolted).
• Loosen the air duct clamps using an 8mm socket or flat-blade screwdriver.
• Disconnect any small breather hose(s) using pliers, then lift the duct out.

Step 2: Unplug the throttle body and clear access

• Unplug the throttle body electrical connector (press the lock tab by hand; use a trim clip removal tool gently if needed).
• If a bracket or harness blocks access, remove its bolts using a 10mm socket and move it aside.
• Tip: Don’t pull on wires—pull on connectors.

Step 3: Remove the upper intake (to reach rear plugs)

• Disconnect vacuum/PCV hoses from the upper intake using pliers.
• Remove the upper intake fasteners using a 12mm socket with a 3/8" drive extension.
• Lift the upper intake straight up and off. If it feels stuck, gently rock it—do not pry hard.
• Immediately place clean rags in the exposed intake ports to keep debris out.

Step 4: Remove ignition coils (one cylinder at a time)

• Pick one cylinder to start with so parts don’t get mixed up.
• Unplug the ignition coil connector.
• Remove the coil hold-down bolt using a 10mm socket.
• Twist the coil slightly, then pull it straight up.
• Torque (coil bolt on install): Torque to 8 Nm (71 in-lbs)
• Ignition coil: the plug-wire “boot” assembly.

Step 5: Clean the spark plug well

• Blow out the spark plug tube/well using a compressed air blow gun.
• This prevents dirt from falling into the cylinder when the plug comes out.

Step 6: Remove the old spark plug

• Install a 14mm thin-wall spark plug socket on a 3/8" drive extension and 3/8" drive ratchet.
• Turn counterclockwise to remove the spark plug.
• If it feels extremely tight, stop and work it slowly to avoid thread damage.

Step 7: Check gap and install the new spark plug

• Check the new plug gap with a feeler gauge set (gap is usually pre-set on OEM-type iridium plugs; do not force-bend fine-wire tips).
• Start the new plug by hand using the spark plug socket and extension only (no ratchet) to avoid cross-threading.
• Once hand-snug, use a torque wrench 3/8" drive.
• Torque (spark plugs): Torque to 18 Nm (13 ft-lbs)
• Tip: Hand-thread first, always.

Step 8: Reinstall the ignition coil

• Apply a small dab of dielectric grease inside the coil boot (this helps prevent moisture and makes future removal easier).
• Push the coil straight down until it fully seats on the plug.
• Install the coil bolt with a 10mm socket, then tighten with a torque wrench 1/4" drive.
• Torque (coil bolt): Torque to 8 Nm (71 in-lbs)
• Reconnect the coil electrical connector until it clicks.

Step 9: Repeat for all 8 cylinders

• Repeat Steps 4–8 until all plugs are replaced.
• Use a pickup magnet tool if you drop a bolt—don’t leave hardware in the valley.

Step 10: Reinstall upper intake and throttle body connections

• Remove rags from the intake ports.
• Install new upper intake gaskets, then set the upper intake in place.
• Install fasteners finger-tight first, then tighten evenly using a 12mm socket.
• Reconnect all vacuum/PCV hoses using pliers.
• Reconnect the throttle body electrical connector.

Step 11: Reinstall intake duct and engine cover

• Reinstall the intake duct and tighten clamps using an 8mm socket or flat-blade screwdriver.
• Reinstall the engine cover.
• Reconnect the negative battery cable using a 10mm socket.

---

✅ After Repair

• Start the engine and let it idle for 2–3 minutes.
• Listen for hissing (vacuum leak) around the upper intake and check that idle is smooth.
• Verify there is no check engine light. If the idle is unstable after battery disconnect, an idle relearn may be needed with a scan tool.
• Take a short test drive and re-check for any loose clamps/hoses.

---

💰 DIY vs Shop Cost

Shop Cost: $450-$900 (parts + labor)

DIY Cost: $80-$200 (parts only)

You Save: $370-$700 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2.5-4.5 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.