🔧 Altima - Ignition Coil Replacement

Your Altima’s ignition coils sit on top of the engine and send high voltage to the spark plugs. A failed coil can cause misfires, rough running, flashing check-engine light, and poor acceleration. Replacing coils is a straightforward bolt-on repair.

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

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⚠️ Safety & Precautions

• ⚠️ Let the engine cool fully before working (hot parts burn).
• ⚠️ Disconnect the negative battery cable to reduce short/misfire risk.
• ⚠️ If the check-engine light is flashing, avoid driving until repaired (can damage the catalytic converter).
• ⚠️ Don’t pull on wiring—release the connector lock first.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" ratchet
• 3" extension for 1/4" ratchet
• Torque wrench (inch-pound, 20-200 in-lb range)
• Flat trim tool
• Needle-nose pliers
• OBD2 scan tool (basic code reader)
• 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 (spark plug boot grease) - Qty: 1
• Intake/engine cover grommets or push clips (as needed) - Qty: 0-4
• Spark plugs (recommended if due) - Qty: 4

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📋 Before You Begin

• Park on level ground, shift to Park, and set the parking brake.
• Open the hood and let the engine cool.
• Use a 10mm socket to disconnect the negative battery terminal and move it aside so it can’t spring back.
• Tip: Take a quick photo of connectors first.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover (if equipped)

• Grab the cover near the corners and pull straight up to release it, or remove fasteners using a flat trim tool (if your cover uses push clips).
• Set the cover aside where it won’t get stepped on.

Step 2: Locate the ignition coils

• The coils are the four identical modules on top of the engine, each held by one bolt and one electrical connector.

Step 3: Unplug the coil electrical connector

• Press the connector lock tab and pull the connector straight off the coil.
• If it’s stubborn, use needle-nose pliers gently on the connector body (not the wires).
• Tip: Wiggle slightly—don’t yank.

Step 4: Remove the coil hold-down bolt

• Use a 10mm socket, 1/4" ratchet, and 3" extension to remove the single bolt holding the coil.

Step 5: Remove the ignition coil

• Twist the coil gently left-right to break the boot loose, then pull straight up.
• If you see oil in the spark plug tube, stop and note it—this can indicate a valve cover gasket tube seal leak.

Step 6: Prep and install the new coil

• Add a small dab of dielectric grease inside the new coil boot (this helps prevent sticking and moisture issues).
• Push the new coil straight down until it fully seats on the spark plug.

Step 7: Reinstall and torque the coil bolt

• Hand-start the bolt to avoid cross-threading.
• Use a torque wrench (inch-pound) to tighten the bolt: Torque to 7.2 Nm (64 in-lb).

Step 8: Reconnect the coil connector

• Push the connector on until you feel/hear it click.
• Give it a gentle tug to confirm it’s locked.

Step 9: Repeat for any other coils being replaced

• Repeat Steps 3-8 for the remaining cylinders if you’re replacing more than one coil.
• Tip: Do one coil at a time to avoid mix-ups.

Step 10: Reinstall engine cover and reconnect the battery

• Reinstall the engine cover (push down evenly until seated).
• 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.
• Use an OBD2 scan tool to clear any stored misfire codes, then re-check for codes after a short test drive.
• Take a 10-15 minute drive with light/moderate throttle and confirm the check-engine light stays off.
• If it still misfires, the next most common causes are spark plugs, a fuel injector issue, or a vacuum leak.

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💰 DIY vs Shop Cost

Shop Cost: $220-$550 (parts + labor)

DIY Cost: $60-$320 (parts only)

You Save: $160-$230 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.