🔧 Spark Plugs - Replacement

Your Silverado uses coil-on-plug ignition, so each plug is accessed by removing the ignition coil first. Replacing all eight plugs restores ignition performance, helps prevent misfires, and can improve fuel economy and throttle response.

Difficulty Level: Intermediate | Estimated Time: 2-4 hours

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⚠️ Safety & Precautions

• Let the engine cool completely before starting. Hot aluminum cylinder heads can damage threads.
• Disconnect the negative battery cable before removing coils to reduce the chance of electrical damage.
• Keep dirt out of the plug wells. Debris can fall into the cylinder when the plug is removed.
• Use a torque wrench. Over-tightening can strip the cylinder head threads.
• Replace plugs one cylinder at a time if you want to stay organized.

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🔧 Required Tools

You'll need the following tools for this repair:

• 1/4-inch drive ratchet
• 3/8-inch drive ratchet
• 5/8-inch spark plug socket
• 10mm socket
• 6-inch extension
• Torque wrench
• Flat-blade trim tool
• Dielectric grease
• Safety glasses
• Nitrile gloves
• Shop vacuum
• Compressed air

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs - Qty: 8
• Ignition coil boots - Qty: 8

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📋 Before You Begin

• Park on level ground and set the parking brake.
• Let the engine cool fully.
• Disconnect the negative battery cable with a 10mm socket.
• Clean around each coil and plug well with compressed air before removal.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Disconnect battery

• Use a 10mm socket to remove the negative battery cable.
• Move the cable aside so it cannot spring back onto the terminal.

Step 2: Access the ignition coils

• If needed, remove the engine cover by hand or with a flat-blade trim tool.
• On this engine, the plugs sit under the ignition coils on top of the valve covers.

Step 3: Remove one ignition coil at a time

• Unplug the electrical connector from the first coil.
• Use a 10mm socket to remove the coil hold-down bolt.
• Twist the coil slightly and pull it straight up.
• Keep each coil and boot with its cylinder.

Step 4: Clean the plug well

• Use compressed air and a shop vacuum to remove dirt from around the spark plug.
• This keeps debris out of the cylinder when the plug comes out.

Step 5: Remove the old spark plug

• Use a 5/8-inch spark plug socket, 6-inch extension, and ratchet to remove the plug.
• Turn it counterclockwise and lift it out carefully.

Step 6: Install the new spark plug

• Check the new plug gap if needed. A spark plug gap is the small space at the tip where the spark jumps.
• Thread the plug in by hand first using the 5/8-inch spark plug socket and extension.
• Once seated by hand, tighten with a torque wrench to 18 Nm (13 ft-lbs).
• Start every plug by hand.

Step 7: Service the coil boot

• Apply a small amount of dielectric grease inside the new or cleaned coil boot.
• Dielectric grease is a silicone grease that helps seal out moisture and makes future removal easier.

Step 8: Reinstall the ignition coil

• Push the coil straight down onto the spark plug.
• Install the hold-down bolt with a 10mm socket and tighten to 10 Nm (89 in-lbs).
• Reconnect the coil electrical connector.

Step 9: Repeat for all cylinders

• Move cylinder by cylinder until all eight spark plugs are replaced.
• Do not mix up coil parts between cylinders.

Step 10: Reconnect battery and verify repair

• Reconnect the negative battery cable with a 10mm socket.
• Start the engine and listen for smooth idle.
• Check the dash for a check engine light or misfire warning.

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✅ After Repair

• Test drive the truck and confirm normal acceleration and idle quality.
• If the check engine light was on, clear codes with a scan tool after confirming the repair.
• If a misfire returns, recheck coil connectors and plug torque.

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💰 DIY vs Shop Cost

Shop Cost: $250-$500 (parts + labor)

DIY Cost: $60-$140 (parts only)

You Save: $190-$360 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2-4 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.