🔧 BRZ - Ignition Coil Replacement

Your BRZ uses four ignition coils (one per cylinder) to fire the spark plugs. A bad coil can cause a misfire, rough idle, flashing check-engine light, and loss of power. Replacing a coil is straightforward, but access is tight, so take your time.

Difficulty Level: Intermediate | Estimated Time: 1.0-2.0 hours

---

⚠️ Safety & Precautions

• ⚠️ Let the engine cool fully before starting (hot parts burn).
• ⚠️ Disconnect the negative battery terminal to prevent electrical shorting.
• ⚠️ Support the battery so it can’t tip and leak.
• ⚠️ Do not pull on wiring—release connector locks first.

---

🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 3/8" ratchet
• 6" extension (3/8")
• Torque wrench (inch-pound)
• Flat trim tool
• Needle-nose pliers
• OBD-II scan tool (basic)
• Nitrile gloves
• Safety glasses
• Fender cover

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

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

---

📋 Before You Begin

• 🅿️ Park on level ground, put the transmission in neutral, and set the parking brake.
• 🔧 Open the hood and install a fender cover to protect paint.
• 🔋 Disconnect the battery negative terminal using a 10mm socket and move the cable aside so it can’t spring back.
• 🧠 If the check-engine light is on, plug in an OBD-II scan tool (a small code reader) and write down any misfire codes (P0301–P0304) before disconnecting the battery.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover (if equipped)

• Use your hands to pull up and remove the engine cover from its rubber grommets.
• Pull straight up; don’t twist hard.

Step 2: Create access to the coils

• On the passenger side, remove the battery hold-down using a 10mm socket and 3/8" ratchet, then lift the battery out.
• On the driver side, loosen intake/airbox fasteners as needed using a 10mm socket and release clips with a flat trim tool to move the airbox/ducting for hand clearance.
• Set parts and bolts aside in a small tray so nothing gets lost.

Step 3: Unplug the ignition coil connector

• Locate the coil on top of the cylinder head (one per cylinder).
• Press the electrical connector lock tab and pull the connector straight off.
• If the tab is stubborn, gently help it with a flat trim tool (don’t pry on the wires).

Step 4: Remove the ignition coil

• Remove the coil hold-down bolt using a 10mm socket, 3/8" ratchet, and 6" extension (3/8").
• Wiggle and pull the coil straight out of the spark plug tube.
• If it’s stuck, twist the coil boot slightly by hand while pulling.

Step 5: Install the new ignition coil

• Apply a tiny smear of dielectric grease inside the coil boot (this helps moisture protection and easier removal later).
• Push the new coil straight down until it seats fully on the spark plug.
• Install the hold-down bolt by hand first (to avoid cross-threading), then tighten with a 10mm socket.
• Final tighten with a torque wrench (inch-pound): Torque to 7.5 Nm (66 in-lbs).

Step 6: Reconnect the coil connector

• Push the connector on until you feel/hear it click into place.
• Gently tug to confirm it’s locked.

Step 7: Repeat for any other coils being replaced

• Repeat Steps 3–6 for the remaining cylinders you’re servicing.
• If one coil failed, many owners replace all four.

Step 8: Reinstall removed components

• Reinstall the airbox/ducting and tighten fasteners using a 10mm socket.
• Reinstall the battery and battery hold-down using a 10mm socket.
• Reconnect the negative battery terminal using a 10mm socket.
• Reinstall the engine cover by pressing it down into the grommets.

---

✅ After Repair

• ✅ Start the engine and let it idle for 1–2 minutes; it should run smooth with no flashing check-engine light.
• ✅ Use an OBD-II scan tool to clear any stored misfire codes, then recheck for pending codes after a short drive.
• ✅ Take a 10–15 minute test drive and confirm acceleration feels normal.
• ✅ If you still have a misfire, the next common checks are the spark plug, injector, or vacuum leak on that cylinder.

---

💰 DIY vs Shop Cost

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

DIY Cost: $60-$400 (parts only, depending on replacing 1 vs 4)

You Save: $150-$300+ by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.0-2.0 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.