🔧 Altima - Ignition Coil Replacement

Your Altima uses one ignition coil per cylinder (4 total). Replacing a bad coil restores smooth running and helps prevent misfires that can damage the catalytic converter.

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

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⚠️ Safety & Precautions

• Turn the car fully OFF and remove the key/fob from the vehicle area so it cannot go into READY mode.
• Let the engine cool before working near the valve cover and exhaust side.
• Disconnect the 12V battery negative cable to prevent accidental starts and protect electronics.
• Do not touch or pull on wiring; always press the connector lock tab and pull on the connector body.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" drive ratchet
• 6" extension (1/4" drive)
• Torque wrench (inch-pound)
• Small flathead screwdriver
• Pick tool
• Needle-nose pliers
• Shop towels
• Nitrile gloves
• Safety glasses
• OBD2 scan tool

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 4 Replace as needed; many replace all.
• Dielectric grease (spark plug boot grease) - Qty: 1

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📋 Before You Begin

• Park on level ground and set the parking brake.
• Open the hood and allow the engine to cool.
• Disconnect the 12V battery negative terminal: use a 10mm socket and move the cable aside so it can’t spring back.
• If you’re chasing a misfire, note any stored codes with an OBD2 scan tool (example: P0301 = cylinder 1 misfire).

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover (if equipped)

• Remove the engine cover fasteners using a 10mm socket and 1/4" drive ratchet.
• Lift the cover straight up and set it aside.

Step 2: Locate the ignition coils

• The coils sit on top of the valve cover, one per cylinder, each with an electrical connector.
• Use shop towels to wipe dirt away around each coil so debris doesn’t fall into the spark plug hole.

Step 3: Unplug the coil electrical connector

• Press the connector lock tab and pull the connector off by hand.
• If it’s stuck, use a small flathead screwdriver gently on the lock tab (do not pry hard). Small moves; don’t crack the connector.
• If the rubber seal is holding it, a pick tool can help break the seal lightly at the edge.

Step 4: Remove the coil hold-down bolt

• Remove the coil bolt using a 10mm socket, 6" extension (1/4" drive), and 1/4" drive ratchet.
• Set the bolt somewhere safe so it doesn’t fall into the engine bay.

Step 5: Remove the ignition coil

• Twist the coil slightly left-right, then pull straight up to remove it.
• If it won’t move, pull steadily while twisting (don’t use pliers on the coil body).

Step 6: Prep and install the new coil

• Put a small smear of dielectric grease inside the new coil boot (the rubber “tube” that seals to the spark plug). Dielectric grease is non-conductive grease that helps prevent moisture intrusion and eases future removal.
• Push the new coil straight down until it fully seats on the spark plug.

Step 7: Reinstall and torque the coil bolt

• Start the bolt by hand a few turns to avoid cross-threading.
• Tighten with a torque wrench (inch-pound): Torque to 7.2 Nm (63 in-lbs).

Step 8: Reconnect the coil connector

• Push the connector on until it clicks.
• Gently tug to confirm it’s locked.

Step 9: Repeat for the remaining coils

• Repeat Steps 3-8 for the other cylinders.
• Keep bolts and connectors matched to their locations.

Step 10: Reinstall the engine cover and reconnect the 12V battery

• Reinstall the engine cover using a 10mm socket and 1/4" drive ratchet.
• Reconnect the 12V battery negative cable using a 10mm socket.

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✅ After Repair

• Start the car and confirm it idles smoothly (no shaking, no flashing check-engine light).
• Use an OBD2 scan tool to clear misfire codes and confirm they don’t return.
• Test drive 10-15 minutes and recheck for warning lights.
• If a misfire remains on the same cylinder after coil replacement, the next common check is the spark plug (not the coil).

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💰 DIY vs Shop Cost

Shop Cost: $250-$700 (parts + labor)

DIY Cost: $120-$480 (parts only)

You Save: $130-$220 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1.0 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.