🔧 Spark Plugs - Replacement

Replacing the spark plugs will restore ignition performance, help prevent misfires, and can improve idle quality and fuel economy. On your Silverado, the 6.2L V8 uses long-reach plugs, so clean work and correct torque matter a lot.

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

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⚠️ Safety & Precautions

• Work on a cool engine only. Hot aluminum cylinder heads can be damaged easily.
• Disconnect the negative battery cable before starting. This helps prevent accidental starts and module faults.
• Keep dirt out of the spark plug wells. Debris can fall into the cylinders.
• Do not use anti-seize on the plug threads unless the plug manufacturer specifically calls for it.
• Use only the correct plug type and gap for the 6.2L V8.

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🔧 Required Tools

You'll need the following tools for this repair:

• 5/8-inch spark plug socket
• 3/8-inch drive ratchet
• 3/8-inch drive extension set
• 10mm socket
• Torx T20 screwdriver
• Torque wrench
• Feeler gauge
• Compressed air
• Trim clip tool
• Needle-nose pliers
• Battery terminal wrench
• Gloves
• Safety glasses

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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
• Dielectric grease - Qty: 1

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📋 Before You Begin

• Park on level ground and set the parking brake.
• Let the engine cool fully before touching the ignition system.
• Disconnect the negative battery cable using a 10mm socket.
• Remove the engine cover before reaching the rear coils.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Disconnect power

• Use a 10mm socket to disconnect the negative battery cable.
• Move the cable aside so it cannot touch the terminal.

Step 2: Remove the engine cover

• Lift the engine cover straight up by hand.
• If it feels stuck, gently work it upward evenly.

Step 3: Remove ignition coils

• Use a 10mm socket to remove each ignition coil bolt.
• Unplug the coil connector carefully by pressing the release tab.
• Pull each coil straight up. Twist gently if needed.

Step 4: Clean the plug wells

• Use compressed air to blow dirt away from each spark plug well.
• Make sure no debris falls into the cylinder before removing the plug.

Step 5: Remove the old spark plugs

• Use a 5/8-inch spark plug socket, 3/8-inch extension, and ratchet to remove each plug.
• Turn counterclockwise slowly to avoid damaging the threads.
• Inspect the removed plugs for oil, heavy wear, or cracking.

Step 6: Check and install the new plugs

• Use a feeler gauge to verify the gap on each new plug.
• Install each plug by hand first using the spark plug socket and extension.
• Once seated, tighten with a torque wrench to 25 Nm (18 ft-lbs).
• Hand-start every plug first.

Step 7: Reinstall ignition coils

• Apply a small amount of dielectric grease inside each coil boot.
• Push each coil straight down onto its spark plug.
• Reinstall the coil bolts with a 10mm socket and tighten to 10 Nm (89 in-lbs).
• Reconnect each coil connector until it clicks.

Step 8: Reassemble

• Reinstall the engine cover by pressing it into place.
• Reconnect the negative battery cable with a 10mm socket.

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✅ After Repair

• Start the engine and listen for smooth idle.
• Check for a check engine light or misfire.
• If the engine runs rough, recheck coil connectors and plug installation.
• Drive the vehicle and make sure acceleration feels normal.

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💰 DIY vs Shop Cost

Shop Cost: $350-$650 (parts + labor)

DIY Cost: $80-$180 (parts only)

You Save: $270-$470 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2-3 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.