🔧 CX-5 - Ignition Coil Replacement

Ignition coils sit on top of each spark plug and create the high voltage needed to fire the plug. Replacing a bad coil can fix misfires, rough idle, and flashing check-engine lights.

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

---

⚠️ Safety & Precautions

• ⚠️ Work on a cool engine to avoid burns.
• ⚠️ Keep the key fob away from the vehicle and make sure ignition is OFF.
• ⚠️ Don’t pull on wiring—only pull on connectors.
• ⚠️ Battery disconnect is not required, but if you’re nervous around electrical connectors, disconnect the negative terminal first.

---

🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" ratchet
• 6" socket extension (1/4")
• Torque wrench (in-lb)
• Small flathead screwdriver
• Nitrile gloves
• Safety glasses
• OBD2 scan tool

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1 (or Qty: 4 if replacing all)
• Dielectric grease - Qty: 1

---

📋 Before You Begin

• Park on level ground and let the engine cool fully.
• If you have an OBD2 scan tool, scan and write down any codes (example: P0301 = cylinder 1 misfire).
• Replace coils in sets if high mileage.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover (if equipped)

• Pull straight up on the cover using your hands; it’s held by rubber grommets.
• If it feels stuck, gently lift at each corner a little at a time.

Step 2: Locate the ignition coils

• You’ll see 4 coils lined up on top of the valve cover, each with an electrical connector and a small hold-down bolt.

Step 3: Unplug the coil electrical connector

• Use a small flathead screwdriver to gently help lift the lock tab if needed (don’t pry hard).
• Press the tab and pull the connector straight off by hand.
• If it won’t move, wiggle—don’t yank.

Step 4: Remove the coil hold-down bolt

• Use a 10mm socket, 1/4" ratchet, and 6" extension to remove the bolt.
• Set the bolt aside where it won’t fall into the engine bay.

Step 5: Remove the ignition coil

• Grab the coil body and twist it slightly left/right to break the seal.
• Pull the coil straight upward to remove it.
• Term: The rubber “boot” is the long insulated sleeve on the coil that seals around the spark plug.

Step 6: Prep and install the new coil

• Apply a very small dab of dielectric grease inside the end of the new coil boot (pea-sized). This helps prevent moisture and makes future removal easier.
• Push the new coil straight down until it fully seats on the spark plug.

Step 7: Reinstall the coil bolt and torque it

• Start the bolt by hand to avoid cross-threading.
• Use a 10mm socket to snug it down.
• Use a torque wrench (in-lb): Torque to 71-89 in-lbs (8-10 N·m).

Step 8: Reconnect the electrical connector

• Push the connector on until it clicks.
• Gently tug to confirm it’s locked.

Step 9: Repeat for any other coils you’re replacing

• Use the same 10mm socket process coil-by-coil.
• Do one coil at a time to avoid mix-ups.

Step 10: Reinstall the engine cover

• Line up the cover grommets and press down firmly by hand until it seats.

---

✅ After Repair

• Use an OBD2 scan tool to clear codes if the check-engine light was on.
• Start the engine and let it idle for 1-2 minutes. Listen/feel for smooth running.
• Test drive for 10-15 minutes. If the check-engine light flashes or it runs rough, stop and re-check each connector is fully clicked in.

---

💰 DIY vs Shop Cost

Shop Cost: $250-$650 (parts + labor)

DIY Cost: $60-$400 (parts only)

You Save: $190-$250 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.7-1.2 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.