🔧 Ignition Coils - Replacement

Your Silverado uses individual coil-on-plug ignition coils, one per spark plug. Replacing a failed coil can fix misfires, rough idle, poor power, and check engine lights. If one coil has failed due to age or oil contamination, it’s smart to inspect the nearby spark plug and boot too.

Difficulty Level: Beginner | Estimated Time: 1-2 hours

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⚠️ Safety & Precautions

• Let the engine cool completely before starting.
• Disconnect the negative battery cable before working on ignition components.
• Do not pull on the wiring harness; release the connector lock first.
• Keep metal tools away from the battery and starter area.
• If a coil has oil on it, inspect the valve cover and spark plug well for leaks.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 8mm socket
• Ratchet
• 3-inch extension
• Trim tool
• Dielectric grease
• Torque wrench
• Gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 8
• Spark plug boots - Qty: 8
• Dielectric grease - Qty: 1
• Valve cover gasket set - Qty: 1 if oil leak is present

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📋 Before You Begin

• Park on level ground and set the parking brake.
• Turn the ignition off and remove the key fob from the vehicle.
• Disconnect the negative battery cable using an 8mm socket.
• Work on one coil at a time so the wiring stays organized.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Disconnect battery power

• Use an 8mm socket to remove the negative battery cable.
• Move the cable aside so it cannot spring back and reconnect.

Step 2: Remove the engine cover if equipped

• Lift the cover straight up by hand.
• If it feels stuck, gently work it loose with a trim tool.

Step 3: Access the ignition coils

• Locate the coil on each valve cover area.
• Each coil sits directly on top of a spark plug.
• One coil serves one cylinder.

Step 4: Unplug the coil connector

• Release the connector lock by hand.
• Pull the connector straight off the coil.
• Do not yank on the wires.

Step 5: Remove the coil hold-down bolt

• Use an 8mm socket with a ratchet and extension to remove the bolt.
• Set the bolt aside where it will not get lost.
• Torque on installation: 10 Nm (89 in-lbs)

Step 6: Remove the ignition coil

• Twist the coil slightly to break the seal.
• Pull the coil straight up off the spark plug.
• If the coil boot stays in the spark plug tube, remove it carefully.

Step 7: Inspect the spark plug and boot

• Look for oil, cracks, or carbon tracking on the boot.
• If the plug well has oil, the valve cover gasket may be leaking.
• Apply a thin film of dielectric grease inside the new boot. Dielectric grease is a silicone grease that helps moisture resistance and easy removal.

Step 8: Install the new ignition coil

• Push the new coil straight down onto the spark plug until fully seated.
• Install the hold-down bolt by hand first.
• Use an 8mm socket to tighten the bolt to 10 Nm (89 in-lbs).

Step 9: Reconnect the coil connector

• Push the connector onto the coil until it clicks.
• Make sure the lock is fully engaged.

Step 10: Repeat for the remaining coils

• Replace the other coils the same way if you are doing all eight.
• If only one coil failed, inspect the others for cracks or oil contamination.

Step 11: Reinstall covers and reconnect battery

• Reinstall the engine cover by hand.
• Reconnect the negative battery cable using an 8mm socket.

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✅ After Repair

• Start the engine and listen for smooth idle.
• Check for a misfire or flashing check engine light.
• If a scan tool is available, clear any stored misfire codes.
• Test drive the truck and confirm normal acceleration.
• If the old coil failed because of an oil leak, repair the leak soon.

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💰 DIY vs Shop Cost

Shop Cost: $320-$900 (parts + labor)

DIY Cost: $160-$520 (parts only)

You Save: $160-$380 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1-2 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.