How to Replace Ignition Coils on a 2015-2019 Subaru Outback 2.5L (DIY Guide) (Engine: Flat 4 2.5L)
Step-by-step instructions with tools, parts list, safety tips, and ignition coil bolt torque specs
How to Replace Ignition Coils on a 2015-2019 Subaru Outback 2.5L (DIY Guide) (Engine: Flat 4 2.5L)
Step-by-step instructions with tools, parts list, safety tips, and ignition coil bolt torque specs for 2015, 2016, 2017, 2018, 2019
🔧 Outback - Ignition Coil Replacement
Ignition coils create the high voltage your A4’s spark plugs need to fire. When a coil fails, you’ll often get a misfire (rough idle, flashing check engine light, loss of power). This job is straightforward on your Outback because the coils are accessible on top of the engine.
Assumption: Stock 2.5L engine layout; coil hold-down uses a single small bolt per coil.
Difficulty Level: Beginner | Estimated Time: 0.8-1.5 hours
⚠️ Safety & Precautions
- ⚠️ Work on a cold engine to avoid burns.
- ⚠️ Disconnect the negative battery terminal to prevent accidental short circuits.
- ⚠️ If the check engine light is flashing, avoid driving until repaired (can damage the catalytic converter).
- ⚠️ Don’t pull on wiring—only on connectors and the coil body.
🔧 Required Tools
You'll need the following tools for this repair:
- 10mm socket
- 12mm socket
- 3/8" ratchet
- 3" extension
- Torque wrench (inch‑pound or small Nm range)
- Flathead screwdriver
- Trim clip removal tool
- Nitrile gloves
- Safety glasses
- OBD‑II code reader (specialty)
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Ignition coil - Qty: 1-4
- Dielectric grease - Qty: 1
📋 Before You Begin
- 🅿️ Park on level ground, shift to Park, and set the parking brake.
- 🧊 Let the engine cool fully (coils sit near hot cylinder heads).
- 🔋 Disconnect the battery negative cable using a 10mm socket and tuck it aside so it can’t spring back.
- 🧠 If you have a scan tool: use an OBD‑II code reader (specialty) (plugs into the diagnostic port) to record any codes before you start.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Remove the engine cover (if equipped)
- Grip the cover with both hands and pull straight upward to release the rubber grommets.
- Set it aside where it won’t get stepped on.
Step 2: Create working room (intake duct/snorkel if it blocks access)
- Use a flathead screwdriver to loosen any hose clamp that limits access.
- Use a trim clip removal tool to pop any plastic push-clips without breaking them.
- Move the ducting aside gently (no need to force it).
Step 3: Unplug the ignition coil electrical connector
- Locate the coil on top of the cylinder head (one per cylinder).
- Press the connector lock tab with your thumb; if it’s stubborn, use a flathead screwdriver gently.
- Pull the connector straight off (don’t yank the wires).
Step 4: Remove the ignition coil hold-down bolt
- Use a 12mm socket, 3/8" ratchet, and 3" extension to remove the bolt.
- Put the bolt somewhere safe so it doesn’t disappear.
Step 5: Remove the ignition coil
- Twist the coil slightly left-right to break the boot’s seal.
- Pull the coil straight up and out.
- If it feels stuck, keep twisting—don’t pry hard.
Step 6: Prep and install the new ignition coil
- Apply a tiny smear of dielectric grease inside the rubber boot (this helps prevent moisture and makes future removal easier).
- Line the coil up with the spark plug tube and push down firmly until it seats fully.
Step 7: Reinstall and torque the coil bolt
- Start the bolt by hand first (prevents cross-threading).
- Tighten with a 12mm socket until snug.
- Finish with a torque wrench (inch‑pound or small Nm range): Torque to 7.5 Nm (5.5 ft-lbs).
Step 8: Reconnect the coil connector
- Push the connector on until it clicks/locks.
- Give it a gentle tug to confirm it’s fully seated.
Step 9: Repeat for the remaining coils (if replacing more than one)
- Repeat Steps 3–8 for each coil you’re replacing.
- Replacing coils as a set helps prevent repeat failures.
Step 10: Reassemble and reconnect the battery
- Reinstall any intake ducting/clips using the trim clip removal tool and flathead screwdriver as needed.
- Reinstall the engine cover by pushing straight down onto the grommets.
- Reconnect the negative battery cable using a 10mm socket (snug, not over-tight).
✅ After Repair
- 🔍 Start the engine and let it idle for 1–2 minutes. It should run smooth with no shaking.
- 🧪 Do a short test drive and verify normal power delivery.
- 🛠️ If the check engine light stays on, use an OBD‑II code reader (specialty) to clear codes and confirm none return.
- 👃 If you smell fuel or hear arcing/clicking near a coil, shut off and re-check connector seating.
💰 DIY vs Shop Cost
Shop Cost: $250-$650 (parts + labor, depending on how many coils)
DIY Cost: $60-$400 (parts only, depending on how many coils)
You Save: $190-$250+ by doing it yourself!
Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.8-1.5 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.

















