🔧 Tundra - Spark Plug Replacement

On your Tundra, spark plugs wear over time and can cause misfires, rough idle, poor fuel economy, and hard starts. Replacing them restores proper ignition and helps protect the catalytic converters from damage caused by misfires.

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

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⚠️ Safety & Precautions

• ⚠️ Work on a fully cool engine to avoid burns and damaged threads.
• ⚠️ Disconnect the negative battery cable to reduce risk of shorting coils.
• ⚠️ Keep dirt out of the spark plug holes; contamination can damage the engine.
• ⚠️ Do not over-tighten spark plugs; the cylinder heads are aluminum.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• 10mm socket
• 3/8" drive ratchet
• 3/8" drive torque wrench (10–30 ft-lbs range)
• 5/8" spark plug socket
• 3/8" drive extension set (3", 6", 12")
• Universal joint adapter for 3/8" drive
• Trim clip removal tool
• Needle-nose pliers
• Compressed air blow gun
• Feeler gauge set
• Small telescoping mirror

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs (iridium, correct application for 5.7L) - Qty: 8
• Dielectric grease - Qty: 1
• Anti-seize compound - Qty: 1

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📋 Before You Begin

• Park on level ground, shift to Park, and set the parking brake.
• Let the engine cool completely (ideally 2+ hours).
• Use 10mm socket to disconnect the negative battery cable and move it aside so it can’t spring back.
• Do one cylinder at a time to avoid mixing parts.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover (if equipped)

• Pull up on the plastic engine cover to release the rubber grommets, or remove fasteners if yours has them using a 10mm socket.
• Set the cover aside where it won’t get stepped on.

Step 2: Clear access to the ignition coils

• On some areas, you may need to remove small plastic clips or wire looms using a trim clip removal tool.
• Use needle-nose pliers only if a clip is stubborn; don’t crush it.

Step 3: Unplug one ignition coil

• Press the lock tab on the coil electrical connector and pull it off by hand.
• Don’t pull on the wires—pull on the connector body.

Step 4: Remove the ignition coil

• Use a 10mm socket with a 3/8" drive ratchet to remove the coil hold-down bolt.
• Twist the coil gently, then pull it straight up and out.
• The “coil” is the plug-top ignition module.

Step 5: Clean around the spark plug tube

• Use compressed air blow gun to blow dirt/debris out of the spark plug well before removing the plug.
• Use a small telescoping mirror to confirm the area is clean.

Step 6: Remove the old spark plug

• Install a 5/8" spark plug socket on a 3/8" drive extension and 3/8" drive ratchet.
• Use a universal joint adapter for 3/8" drive if the angle is tight.
• Turn counterclockwise to loosen and remove the spark plug.

Step 7: Check and set the new spark plug gap (if required)

• Use a feeler gauge set to verify the gap matches the spec listed on the spark plug box for your application.
• Do not pry on iridium tips; they’re fragile.

Step 8: Install the new spark plug by hand first

• Place the new plug into the 5/8" spark plug socket and lower it into the tube using your extension.
• Thread it in by hand (using the extension only, no ratchet) until it seats.
• Hand-threading prevents cross-threading.

Step 9: Torque the spark plug

• Use a 3/8" drive torque wrench (10–30 ft-lbs range) to tighten the plug.
• Torque to 18 Nm (13 ft-lbs).

Step 10: Reinstall the ignition coil

• Apply a tiny smear of dielectric grease inside the coil boot (the rubber part that seals on the plug).
• Push the coil straight down until it fully seats.
• Install the coil bolt using a 10mm socket, then tighten with a torque wrench.
• Torque to 10 Nm (89 in-lbs).

Step 11: Reconnect the coil connector

• Push the connector on until it clicks.
• Repeat Steps 3–11 for the remaining 7 cylinders, one at a time.

Step 12: Reinstall covers and reconnect the battery

• Reinstall any wire looms/clips using the trim clip removal tool as needed.
• Reinstall the engine cover.
• Reconnect the negative battery cable using a 10mm socket.

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✅ After Repair

• Start the engine and let it idle for 1–2 minutes; it should run smooth with no shaking.
• Listen for a ticking sound near a coil (can indicate a loose plug).
• Take a short test drive, then re-check for any warning lights.
• If the Check Engine Light comes on, scan for codes—misfire codes often point to a connector not fully clicked.

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💰 DIY vs Shop Cost

Shop Cost: $450-$850 (parts + labor)

DIY Cost: $90-$220 (parts only)

You Save: $360-$630 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?

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