🔧 Yukon - Ignition Coil Replacement

Your Yukon uses coil-on-plug ignition coils (one coil per cylinder) mounted on the valve covers. Replacing a bad coil can fix misfires, rough idle, and a flashing or steady check-engine light.

Difficulty Level: Beginner | Estimated Time: 0.5-1.5 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a cool engine to avoid burns.
• ⚠️ Keep the key out of the vehicle while unplugging ignition components.
• ⚠️ Disconnect the negative battery cable if you’re worried about shorting a connector or you’ll be leaning over the battery area.
• ⚠️ Do not pull on wiring; press the connector tab and pull on the plastic connector body.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" drive ratchet
• 3" socket extension
• Torque wrench (in-lb or Nm capable)
• Small flat-blade screwdriver
• Trim tool or plastic pry tool
• Needle-nose pliers
• Shop rags
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1 (or Qty: 8 to replace all)
• Dielectric grease - Qty: 1

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📋 Before You Begin

• 🧰 Park on level ground, shift to Park, and set the parking brake.
• 🧰 Open the hood and let the engine fully cool.
• 🧰 If disconnecting the battery: use a 10mm socket to remove the negative cable and tuck it aside so it can’t spring back.
• 🧰 Decide your strategy: replace the single failed coil (most common) or replace all 8 coils at once (preventive).

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover (if equipped)

• Use a trim tool or plastic pry tool to gently lift the cover corners if it’s stuck.
• Lift the cover straight up and set it aside on a clean surface.

Step 2: Locate the ignition coil you’re replacing

• Each cylinder has one coil mounted to the valve cover with an electrical connector and a rubber boot that goes down onto the spark plug.
• Do one coil at a time to avoid mix-ups.

Step 3: Unplug the coil electrical connector

• Use a small flat-blade screwdriver to gently lift the connector lock tab if it has one (don’t pry hard).
• Press the release and pull the connector straight off by hand.
• If it’s tight, use needle-nose pliers only on the connector body very gently (not the wires).

Step 4: Remove the coil mounting bolt(s)

• Use a 10mm socket, 1/4" drive ratchet, and 3" extension to remove the coil bolt(s).
• Set the bolt(s) aside; you will typically reuse them.

Step 5: Remove the ignition coil

• Grab the coil body and twist it slightly left/right to break the seal of the boot.
• Pull straight upward to remove the coil and boot from the spark plug.
• If the boot feels stuck, use a shop rag to improve grip and keep pulling straight up (don’t pry on the valve cover).

Step 6: Prep the new coil (or boot)

• Wipe the spark plug well area with a shop rag if you see dirt.
• Apply a small dab of dielectric grease inside the new coil boot. Dielectric grease is non-conductive grease that helps prevent moisture and makes future removal easier.
• Use a pea-sized amount, not a glob.

Step 7: Install the new coil

• Push the coil straight down onto the spark plug until you feel it fully seat.
• Reinstall the coil mounting bolt(s) by hand first to prevent cross-threading.
• Use a torque wrench (in-lb or Nm capable) to tighten the coil bolt(s): Torque to 10 Nm (89 in-lbs).

Step 8: Reconnect the electrical connector

• Push the connector on until it clicks/locks.
• Gently tug back to confirm it’s fully latched.

Step 9: Reinstall the engine cover

• Line it up with the mounting points and press down evenly by hand until it snaps into place.

Step 10: Reconnect the battery (if disconnected)

• Use a 10mm socket to tighten the negative battery cable clamp snugly.

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✅ After Repair

• ✅ Start the engine and let it idle for 1-2 minutes; it should run smooth with no shaking.
• ✅ If you had a check-engine light, it may take a few drive cycles to go out, or you can clear it with a scan tool (if available).
• ✅ Road test for 10 minutes and recheck for misfire symptoms.
• ✅ If misfire continues on the same cylinder, the next common checks are the spark plug and injector.

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💰 DIY vs Shop Cost

Shop Cost: $250-$900 (parts + labor)

DIY Cost: $40-$720 (parts only)

You Save: $210-$180 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1.5 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.