🔧 Wrangler - Ignition Coil Replacement

Your Wrangler uses coil-on-plug ignition coils (one coil per cylinder). Replacing a bad coil can fix a misfire, rough idle, and a flashing check-engine light, and it’s a straightforward job with basic hand tools.

Difficulty Level: Beginner | Estimated Time: 0.5-1.5 hours

---

⚠️ Safety & Precautions

• ⚠️ Work on a cool engine; coils sit on hot cylinder heads.
• ⚠️ Keep the key out of the ignition while unplugging coils.
• ⚠️ If you disconnect the battery, you may lose radio presets.
• ⚠️ Do not pull on wiring; unplug by the connector body.

---

🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" ratchet
• 3" extension
• 6" extension
• Universal joint wobble adapter
• Small flat-blade screwdriver
• Torque wrench (in-lb)
• Trim clip tool
• Shop light
• Nitrile gloves
• Safety glasses

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1 (or Qty: 6 to replace all)
• Dielectric grease - Qty: 1

---

📋 Before You Begin

• Park on level ground, transmission in neutral, and set the parking brake.
• Let the engine fully cool.
• If you prefer maximum safety, disconnect the negative battery cable using a 10mm socket.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover (if equipped)

• Pull up firmly on the engine cover to release the rubber grommets, or remove any fasteners using a trim clip tool if yours has them.
• Set the cover aside where it won’t get stepped on.

Step 2: Locate the coil you’re replacing

• Use a shop light to find the coil: it’s the small unit bolted to the valve cover with an electrical connector on top.
• Do one coil at a time to avoid mix-ups.

Step 3: Unplug the coil electrical connector

• Use a small flat-blade screwdriver to gently lift the connector lock (if present), then press the tab and pull the connector straight off.
• If it’s stubborn, wiggle the connector—do not yank the wires.

Step 4: Remove the coil retaining bolt

• Remove the single coil bolt using a 10mm socket, 1/4" ratchet, and a 3" or 6" extension.
• For tight rear coils near the firewall, use the universal joint wobble adapter to get the socket aligned. (A wobble adapter is a joint that lets the socket bend slightly.)

Step 5: Remove the coil

• Twist the coil gently left-right to break the boot seal, then pull straight upward to remove it.
• Look down the spark plug tube for oil or water. If you see oil, stop and tell me—there may be a valve cover leak.

Step 6: Prep and install the new coil

• Apply a small smear of dielectric grease inside the rubber boot. (Dielectric grease is a non-conductive grease that helps prevent moisture and makes future removal easier.)
• Push the new coil straight down until it seats fully on the spark plug.

Step 7: Reinstall the coil bolt and tighten to spec

• Start the bolt by hand to prevent cross-threading.
• Tighten with a torque wrench (in-lb): Torque to 9 Nm (80 in-lbs).

Step 8: Reconnect the electrical connector

• Push the connector on until it clicks/locks.
• Give it a gentle tug to confirm it’s fully seated.

Step 9: Repeat for other coils (if replacing more than one)

• Repeat Steps 2–8 for each remaining coil.
• Rear coils need patience and good lighting.

Step 10: Reinstall engine cover and battery connection

• Reinstall the engine cover by pressing it onto the grommets.
• If disconnected, reconnect the negative battery cable using a 10mm socket.

---

✅ After Repair

• Start the engine and let it idle for 1–2 minutes. It should run smooth.
• If the check-engine light was flashing before, it should stop flashing immediately if the misfire is fixed.
• Take a short test drive and recheck for any rough running.
• If the check-engine light stays on, the code may need clearing after the repair.

---

💰 DIY vs Shop Cost

Shop Cost: $180-$500 (parts + labor)

DIY Cost: $35-$330 (parts only)

You Save: $145-$170 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1.2 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.