🔧 Spark Plugs - Replacement

Your Silverado’s spark plugs should be replaced carefully to avoid damaging the threads in the cylinder heads or cracking a coil boot. On the 4.3L V6, access is straightforward, but you’ll need to work methodically so each coil and plug goes back in the right place.

Difficulty Level: Intermediate | Estimated Time: 2-3 hours

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⚠️ Safety & Precautions

• Let the engine cool fully before starting. Hot exhaust parts can burn you.
• Disconnect the negative battery cable before removing ignition coils.
• Keep dirt out of the spark plug holes. Debris can damage the engine.
• Do not overtighten spark plugs. Aluminum threads can strip easily.
• Work one cylinder at a time so wires and parts do not get mixed up.

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🔧 Required Tools

You'll need the following tools for this repair:

• 3/8-inch drive ratchet
• 5/8-inch spark plug socket
• 3-inch extension
• 10mm socket
• Torque wrench
• Dielectric grease
• Anti-seize compound
• Flat-blade screwdriver
• Gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs - Qty: 6
• Ignition coil boots - Qty: 6

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📋 Before You Begin

• Park on level ground and set the parking brake.
• Let the engine cool completely.
• Disconnect the negative battery cable using a 10mm socket.
• Labeling coils helps prevent mix-ups.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Disconnect power

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

Step 2: Remove ignition coil covers and connectors

• If equipped, remove any engine cover by hand.
• Unplug the ignition coil electrical connector on one cylinder at a time.
• Press the connector tab gently before pulling it off.

Step 3: Remove the ignition coils

• Use a 10mm socket to remove each coil hold-down bolt.
• Twist the coil slightly and lift it straight up.
• Inspect the coil boot for oil, cracks, or burns.

Step 4: Remove the old spark plugs

• Use a 5/8-inch spark plug socket with a 3-inch extension and ratchet.
• Turn each plug counterclockwise to remove it.
• If a plug feels stuck, work it slowly to avoid thread damage.

Step 5: Install the new spark plugs

• Check the gap on each new plug if needed. Use the specification on the plug box or service data.
• Apply a tiny amount of anti-seize compound only if the plug manufacturer allows it.
• Start each plug by hand first to avoid cross-threading.
• Use the 5/8-inch spark plug socket to tighten each plug.
• Torque to 18 Nm (13 ft-lbs).

Step 6: Reinstall the 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.
• Torque to 10 Nm (89 in-lbs).
• Reconnect each electrical connector until it clicks.

Step 7: Reassemble and reconnect battery

• Reinstall any engine cover by hand.
• Reconnect the negative battery cable with a 10mm socket.

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✅ After Repair

• Start the engine and listen for smooth idle.
• Check that the check engine light is off.
• If the engine runs rough, recheck coil connectors and plug seating.
• Take a short test drive and confirm normal acceleration.

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💰 DIY vs Shop Cost

Shop Cost: $250-$450 (parts + labor)

DIY Cost: $40-$120 (parts only)

You Save: $210-$330 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-2.5 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.