🔧 Ioniq - Ignition Coil Replacement

Your Ioniq uses coil-on-plug ignition coils (one coil per cylinder) mounted on top of the engine. Replacing a bad coil can fix a misfire, rough running, flashing check-engine light, and loss of power.

Difficulty Level: Beginner | Estimated Time: 0.5-1.0 hours

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⚠️ Safety & Precautions

• ⚠️ Let the engine cool first; coils sit near hot parts.
• ⚠️ Power the car OFF and keep the key fob at least 10 feet away so the hybrid system can’t “READY” itself.
• ⚠️ Do not touch orange high-voltage cables/connectors.
• ⚠️ If you disconnect the 12V battery, you may lose radio presets.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" ratchet
• 6" socket extension (1/4")
• Torque wrench (inch-pound)
• Plastic trim tool
• Small flat screwdriver
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1-4
• Dielectric grease - Qty: 1

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📋 Before You Begin

• Park on level ground and set the parking brake.
• Power the car OFF and remove the key fob from the area.
• If you want maximum safety: disconnect the 12V negative terminal (10mm). The 12V battery is in the rear cargo area under the floor cover on your Ioniq.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover

• Use a plastic trim tool to gently pry up if it’s tight, then lift the cover straight up to release the rubber grommets.
• Pull straight up to avoid cracking it.

Step 2: Locate the ignition coils

• You’ll see 4 coils in a row on top of the engine, each with an electrical connector.
• A coil is the part that makes spark; it sits directly on the spark plug.

Step 3: Unplug the coil electrical connector

• Use a small flat screwdriver only if needed to gently lift the lock tab, then press the release and pull the connector straight back.
• Do not pull on the wires.

Step 4: Remove the coil hold-down bolt

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

Step 5: Remove the ignition coil

• Twist the coil slightly to break the seal, then pull straight up by hand.
• If it’s stuck, keep wiggling gently; don’t pry hard against plastic parts.

Step 6: Install the new ignition coil

• Put a small smear of dielectric grease inside the rubber boot of the new coil (just a thin film).
• Push the coil straight down until it fully seats on the spark plug.
• Reinstall the hold-down bolt by hand first (prevents cross-threading), then tighten with the 10mm socket.
• Final tighten with a torque wrench (inch-pound): Torque to 9.8 Nm (87 in-lbs).

Step 7: Reconnect the electrical connector

• Push the connector on until it clicks/locks.

Step 8: Reinstall the engine cover

• Line up the cover grommets, then press straight down firmly by hand to seat it.

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✅ After Repair

• If you disconnected the 12V battery, reconnect it with the 10mm socket.
• Start your Ioniq and confirm it idles smoothly.
• If you had a check-engine light, it may need to be cleared after the fix (a parts-store scan can do this).
• Road-test gently and confirm no hesitation under acceleration.

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💰 DIY vs Shop Cost

Shop Cost: $180-$450 (parts + labor, depends on how many coils)

DIY Cost: $45-$320 (parts only, depends on how many coils)

You Save: $135-$130 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.

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🎯 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.

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Quick check (so I guide you perfectly):

• ❓ Are you replacing one coil (bad cylinder) or all four as preventive maintenance?
• ❓ Do you have a misfire code like P0301-P0304?