How to Replace Ignition Coils on a 2018 Chevrolet Trax (Fix Misfire & Rough Idle)
Step-by-step coil removal and install with tools list, safety tips, and 10 Nm (89 in-lbs) torque spec for 2015, 2016, 2017, 2018, 2019, 2020, 2021
How to Replace Ignition Coils on a 2018 Chevrolet Trax (Fix Misfire & Rough Idle)
Step-by-step coil removal and install with tools list, safety tips, and 10 Nm (89 in-lbs) torque spec for 2015, 2016, 2017, 2018, 2019, 2020, 2021
đź”§ Trax - Ignition Coil Replacement
Your Trax uses one ignition coil per cylinder to fire the spark plugs. Replacing a weak coil can fix misfires, rough idle, and flashing check-engine symptoms, and it’s a straightforward job on this engine.
Difficulty Level: Beginner | Estimated Time: 0.5-1.0 hours
⚠️ Safety & Precautions
- ⚠️ Let the engine cool fully before starting (hot turbo/engine parts burn).
- ⚠️ Keep the ignition OFF and the key away from the vehicle while unplugging coils.
- ⚠️ If you disconnect the battery, use a 10mm wrench and remove the negative terminal first.
- ⚠️ Do not pull on wiring—release the connector lock and pull the plug body.
đź”§ Required Tools
You'll need the following tools for this repair:
- 8mm socket
- 1/4" drive ratchet
- 1/4" drive extension (3"-6")
- Torque wrench (inch-pound)
- Trim clip tool
- Small flat-blade screwdriver
- Nitrile gloves
- Safety glasses
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Ignition coil - Qty: 1 (or Qty: 4 if replacing all)
- Dielectric grease (optional) - Qty: 1
đź“‹ Before You Begin
- Park on level ground and set the parking brake.
- Open the hood and let the engine cool.
- If you’ve had a flashing check-engine light or strong misfire, avoid driving until repaired.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Remove the engine cover (if equipped)
- Grab the cover near the corners and pull upward to release it from the rubber grommets.
- If a fastener is present on your cover, remove it using an 8mm socket with a 1/4" drive ratchet.
Step 2: Locate the ignition coils
- The coils sit on top of the valve cover, one per cylinder, with an electrical connector on each.
Step 3: Unplug the coil electrical connector
- Use a small flat-blade screwdriver to gently help lift the connector lock if it’s stuck.
- Press the release tab and pull the connector straight off.
- Don’t yank the wires—pull the plastic plug.
Step 4: Remove the ignition coil retaining bolt
- Remove the coil bolt using an 8mm socket, 1/4" drive ratchet, and extension.
- Set the bolt aside where it won’t fall into the engine bay.
Step 5: Remove the ignition coil
- Twist the coil slightly left-right to break the seal, then pull it straight up.
- If it feels stuck, use a trim clip tool gently under the coil ear as a lever (do not pry on the connector).
Step 6: Install the new ignition coil
- If you’re using it, apply a tiny smear of dielectric grease inside the rubber boot (this helps prevent moisture and makes removal easier later).
- Line the coil up with the spark plug hole and push down firmly until fully seated.
Step 7: Reinstall the coil bolt and torque it
- Thread the bolt in by hand first to avoid cross-threading.
- Tighten using an 8mm socket.
- Torque to 10 Nm (89 in-lbs) using a torque wrench (inch-pound).
Step 8: Reconnect the electrical connector
- Push the connector on until it clicks/locks into place.
- Give it a gentle tug to confirm it’s secure.
Step 9: Repeat for other cylinders (if replacing more than one)
- Repeat Steps 3-8 for each remaining coil you’re replacing.
- Replace all four if they’re the same age.
Step 10: Reinstall the engine cover
- Press the cover straight down onto the grommets until it snaps in place.
âś… After Repair
- Start the engine and let it idle for 1-2 minutes. It should run smooth with no shaking.
- If the check-engine light was on, it may take a few drive cycles to clear on its own, or you can clear it with a scan tool.
- Test drive 10-15 minutes. Recheck for any warning lights or rough running.
- If it still misfires, the next common items are spark plugs or a wiring/connector issue at that cylinder.
đź’° DIY vs Shop Cost
Shop Cost: $200-$550 (parts + labor, depending on 1 coil vs all 4)
DIY Cost: $40-$300 (parts only, depending on 1 coil vs all 4)
You Save: $160-$250+ 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.


















