🔧 Gladiator - Spark Plug Replacement

Replacing the spark plugs restores smooth idle, power, and fuel economy, and helps prevent misfires. On your Gladiator’s 3.6L V6, each cylinder has an ignition coil (coil pack) sitting on top of the spark plug, so you’ll remove the coils first, then swap the plugs.

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

---

⚠️ Safety & Precautions

• ⚠️ Work on a fully cool engine to avoid burns and damaged threads.
• ⚠️ Disconnect the negative battery cable to prevent accidental shorts.
• ⚠️ Keep dirt out of the plug holes; blow debris away before removing plugs.
• ⚠️ Start spark plugs by hand only to avoid cross-threading.

---

🔧 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 torque wrench (10-50 ft-lbs range)
• 10mm socket
• 14mm thin-wall spark plug socket
• 3/8" drive extension set (3", 6", 10")
• 3/8" drive wobble extension
• Pick tool
• Trim clip removal tool
• Compressed air blow gun
• Shop towels
• Flashlight

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs (OEM-spec iridium) - Qty: 6
• Dielectric grease - Qty: 1

---

📋 Before You Begin

• Park on level ground, set the parking brake, and chock the wheels.
• Open the hood and let the engine cool completely.
• Disconnect the negative battery cable using a 10mm socket.
• Torque wrench = tool that tightens to an exact value.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover

• Grip the engine cover and pull upward to pop it off the mounting posts.
• Set it aside on a clean surface.

Step 2: Choose a cylinder and unplug the ignition coil

• Work one plug at a time so nothing gets mixed up.
• Use a pick tool to gently lift the lock tab (if equipped), then unplug the coil electrical connector by hand.
• Coil pack = the part that makes spark for that cylinder.

Step 3: Remove the ignition coil

• Remove the coil hold-down bolt using a 10mm socket and 3/8" drive ratchet.
• Twist the coil slightly, then pull it straight up to remove it.
• Wipe any dirt away with shop towels.

Step 4: Clean around the spark plug well

• Use a compressed air blow gun to blow debris away from the spark plug hole before loosening the plug.
• Use a flashlight to confirm the well is clean.

Step 5: Remove the spark plug

• Install a 14mm thin-wall spark plug socket with the needed 3/8" drive extension (use a wobble extension if the angle is tight).
• Loosen and remove the plug with a 3/8" drive ratchet.
• If it feels extremely tight, stop and re-check you’re fully seated on the plug.

Step 6: Install the new spark plug

• Compare the new plug to the old one to ensure matching length and seat style.
• Do not change the gap; install as supplied (these plugs are pre-gapped).
• Thread the new plug in by hand using the 14mm thin-wall spark plug socket and extension only (no ratchet) until fully seated.
• Tighten with a 3/8" drive torque wrench: Torque to 18 Nm (13 ft-lbs).
• Hand-thread first prevents expensive thread damage.

Step 7: Reinstall the ignition coil

• Apply a tiny dab of dielectric grease inside the coil boot (it helps seal out moisture; it does not improve electrical connection).
• Push the coil straight down until it fully seats on the plug.
• Install the coil bolt with a 10mm socket, then tighten with a 3/8" drive torque wrench: Torque to 9 Nm (80 in-lbs).
• Reconnect the electrical connector until it clicks.

Step 8: Repeat for the remaining 5 spark plugs

• Repeat Steps 2–7 for each cylinder.
• Use the wobble extension and longer extensions as needed for the rear cylinders.
• Keep coil connectors routed the same way as original.

Step 9: Reinstall the engine cover and reconnect the battery

• Reinstall the engine cover by aligning it and pressing it down by hand.
• Reconnect the negative battery cable using a 10mm socket.

---

✅ After Repair

• Start the engine and let it idle for 30–60 seconds. It should run smooth with no shaking.
• If the check engine light comes on or it runs rough, re-check each coil connector is fully clicked in.
• Take a short test drive and confirm normal power and no flashing check engine light.

---

💰 DIY vs Shop Cost

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

DIY Cost: $60-$150 (parts only)

You Save: $200-$500 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.

---

🎯 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.