How to Replace Ignition Coils on a 2008 Honda Accord (Fix Misfire & Rough Idle)
Step-by-step coil-on-plug replacement with tools list, parts, safety tips, and 12 Nm (9 ft-lb) torque spec
How to Replace Ignition Coils on a 2008 Honda Accord (Fix Misfire & Rough Idle)
Step-by-step coil-on-plug replacement with tools list, parts, safety tips, and 12 Nm (9 ft-lb) torque spec
🔧 Accord - Ignition Coil Replacement
Your Accord uses “coil-on-plug” ignition coils (one coil per spark plug). Replacing them restores strong spark and can fix misfires, rough idle, and hesitation caused by weak or failed coils.
Difficulty Level: Beginner | Estimated Time: 0.5-1.0 hours
⚠️ Safety & Precautions
- ⚠️ Work on a cool engine to avoid burns.
- ⚠️ Keep hands/tools away from the radiator fan area (it can turn on unexpectedly).
- ⚠️ Disconnect the negative battery cable to prevent accidental shorts.
- ⚠️ Don’t pull on wiring—only pull on connectors.
🔧 Required Tools
You'll need the following tools for this repair:
- 10mm socket
- 1/4" drive ratchet
- 6" socket extension
- Torque wrench (in-lb or low-range ft-lb)
- Flat trim tool
- Shop light
- Nitrile gloves
- Safety glasses
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Ignition coil - Qty: 4
- Dielectric grease - Qty: 1
📋 Before You Begin
- 🅿️ Park on level ground, set the parking brake, and open the hood.
- 🔋 Use a 10mm socket to disconnect the negative battery cable and move it aside so it can’t spring back.
- 🧠 Dielectric grease is a silicone grease that helps keep moisture out of the rubber boot.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Remove the engine cover (if equipped)
- Use a 10mm socket with a 1/4" drive ratchet to remove the engine cover fasteners.
- Lift the cover off and set it aside.
Step 2: Locate the ignition coils
- The coils sit on top of the valve cover in a row (4 total), one per cylinder.
- Use a shop light so you can clearly see each coil connector and bolt.
Step 3: Unplug the coil electrical connector
- Use a flat trim tool to gently help press the connector lock tab (if it’s tight).
- Pull the connector straight off the coil by the plastic housing (not the wires).
Step 4: Remove the coil hold-down bolt
- Use a 10mm socket, 6" socket extension, and 1/4" drive ratchet to remove the coil bolt.
- Set the bolt aside where it won’t fall into the engine bay.
Step 5: Remove the ignition coil
- Grip the coil and gently twist it left-right to break the boot free.
- Pull the coil straight up and out of the spark plug tube.
- If it’s stuck, twist more—don’t pry hard.
Step 6: Prep and install the new coil
- Put a small, thin smear of dielectric grease inside the new coil’s rubber boot (just a light coating).
- Slide the new coil straight down into the spark plug tube until it fully seats.
Step 7: Reinstall and torque the coil bolt
- Thread the bolt in by hand first to avoid cross-threading.
- Use a torque wrench with a 10mm socket to tighten the bolt: Torque to 12 Nm (9 ft-lbs).
- A torque wrench is a tool that tightens fasteners to an exact setting.
Step 8: Reconnect the electrical connector
- Push the connector onto the coil until it clicks/locks in place.
Step 9: Repeat for the remaining coils
- Replace the other 3 coils the same way (recommended to keep them even in age and performance).
- Work one coil at a time to avoid mix-ups.
Step 10: Reinstall the engine cover and reconnect the battery
- Reinstall the engine cover using the 10mm socket and 1/4" drive ratchet.
- Reconnect the negative battery cable using the 10mm socket.
✅ After Repair
- 🧪 Start the engine and let it idle for 1-2 minutes. It should run smooth with no flashing check engine light.
- 🔎 If the check engine light stays on, the stored code may need to be cleared after the fix (or it may clear after a few drive cycles).
- 🛠️ If you found oil down in a spark plug tube, your valve cover gasket or tube seals may be leaking.
- 🚗 Take a short test drive and recheck for any stumble under acceleration.
💰 DIY vs Shop Cost
Shop Cost: $250-$600 (parts + labor)
DIY Cost: $120-$360 (parts only)
You Save: $130-$240 by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1.0 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.


















