🔧 Altima - Ignition Coil Replacement

Your Altima uses one ignition coil per cylinder (4 total). Replacing a bad coil restores a strong spark so the engine runs smooth and stops misfiring.

Difficulty Level: Beginner | Estimated Time: 0.5-1.5 hours

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⚠️ Safety & Precautions

• 🛑 Let the engine cool completely before starting.
• 🛑 Disconnect the negative battery terminal to prevent accidental shorts.
• 🛑 Don’t pull on wires—only unplug connectors by the plastic body.
• 🛑 Keep dirt out of the spark plug tubes (the deep holes under the coils).

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" drive ratchet
• 6" socket extension
• Torque wrench (inch-pound)
• Flat-blade screwdriver
• Needle-nose pliers
• Shop towels
• Flashlight
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1-4
• Dielectric grease - Qty: 1

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📋 Before You Begin

• Park on level ground, set the parking brake, and open the hood.
• Use a 10mm socket to disconnect the negative battery terminal and tuck it aside so it can’t spring back.
• If there’s dust/debris on the valve cover area, wipe it with shop towels first.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Make room to access the coils

• Locate the ignition coils on top of the valve cover (4 identical units in a row).
• If the air intake tube blocks your hands, loosen the hose clamps with a flat-blade screwdriver and move the tube slightly out of the way.
• Take a quick photo of the layout.

Step 2: Unplug the coil electrical connector

• At the first coil, press the connector lock tab and pull the connector straight back.
• If it’s stubborn, gently help the tab with a flat-blade screwdriver (don’t pry hard).
• If the tab breaks, the connector may not stay tight.

Step 3: Remove the coil hold-down bolt

• Use a 10mm socket, ratchet, and extension to remove the coil hold-down bolt.
• Set the bolt somewhere safe (a magnetic tray is handy if you have one).

Step 4: Pull the coil out

• Twist the coil gently left-right to break the seal, then pull straight up to remove it.
• Look down the spark plug tube with a flashlight. It should be dry and clean.
• If you see oil in the tube, stop and don’t install the new coil yet—oil usually means a valve cover/tube seal leak that can ruin coils.

Step 5: Install the new coil

• Put a very small amount of dielectric grease inside the rubber boot of the new coil. (Dielectric grease is a non-conductive grease that helps prevent moisture/corrosion.)
• Slide the coil straight down into the tube until it fully seats on the spark plug.

Step 6: Reinstall the bolt and torque it

• Start the bolt by hand first (prevents cross-threading), then snug it with a 10mm socket.
• Use an inch-pound torque wrench and Torque to 8.7 Nm (77 in-lbs).

Step 7: Plug the connector back in

• Push the electrical connector on until it clicks/locks.
• Gently tug it to confirm it’s latched.

Step 8: Repeat for the remaining coils

• Repeat Steps 2-7 for each coil you’re replacing.
• If you’re replacing all coils, do them one at a time so nothing gets mixed up.

Step 9: Reassemble and reconnect battery

• Reposition the intake tube and tighten clamps with a flat-blade screwdriver (snug, not stripped).
• Reconnect the negative battery terminal 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.
• If the Check Engine Light was on, it may take a few drive cycles to turn off, or you can clear codes with a scan tool.
• Test drive 10-15 minutes and recheck that all connectors are fully seated.

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💰 DIY vs Shop Cost

Shop Cost: $250-$650 (parts + labor)

DIY Cost: $80-$320 (parts only)

You Save: $170-$330 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.7-1.2 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.