🔧 Altima - Ignition Coil Replacement

This is a clean beginner-friendly job, and the ignition coils are now listed in the parts sidebar. Your Altima uses four coil-on-plug units, meaning each spark plug has its own coil sitting directly above it. Replace the diagnosed bad coil, or replace all four if testing confirms multiple failures.

Difficulty Level: Beginner | Estimated Time: 30-60 minutes

Assumption: This procedure is for the listed 2.0L KR20DDET VC-Turbo engine. Nissan’s parts catalog identifies four ignition coils for that engine. nissanpartsdeal.com

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⚠️ Safety & Precautions

• ⚠️ Let the engine cool completely. Turbocharged engine components can remain hot after shutdown.
• 🔑 Keep the ignition switched off and the key away from the car while connectors are unplugged.
• 🔋 Disconnect the negative battery cable if you’re concerned about accidentally switching the ignition on.
• 🧹 Clean around each coil before removal so dirt cannot fall into the spark plug well.
• 🛑 Don’t drive with a flashing check-engine light. A severe misfire can damage the catalytic converter.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 3-inch socket extension
• 1/4-inch drive ratchet
• Inch-pound torque wrench
• 10mm combination wrench
• Small flat-blade screwdriver
• Soft detailing brush
• Compressed-air duster
• OBD-II scan tool
• Mechanic gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1 for one confirmed failed coil
• Ignition coils - Qty: 4 if replacing the complete set
• Dielectric grease - Qty: 1 small tube

The parts sidebar has several matched coil options starting at approximately $38.88 each. I’d normally replace only the failed coil unless the others are also misfiring, damaged, or similarly worn. Parts cannons are loud and expensive.

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📋 Before You Begin

• 🚗 Park your Altima on level ground, select Park, and engage the parking brake.
• ❄️ Wait until the engine is cool enough to touch comfortably.
• 🔑 Switch the ignition completely off and move the key away from the vehicle.
• 📱 Scan for diagnostic trouble codes before disconnecting the battery. A code such as P0301 identifies cylinder 1, P0302 cylinder 2, and so on.
• 📷 Photograph the connectors and coil positions before removing anything.
• 🔋 If disconnecting power, use the 10mm wrench to loosen the negative battery terminal and isolate it from the battery post.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover

• Put on the mechanic gloves and safety glasses.
• If fitted, grip the plastic engine cover near its mounting points and pull it upward evenly.
• Set it aside without twisting or forcing the plastic.
• Nissan notes that some Altimas may not have an engine cover. nialtima.com

Step 2: Locate and clean around the coils

• Locate the four ignition coils along the top of the engine.
• Use the soft detailing brush and compressed-air duster to remove loose dirt around the coil bases.
• Don’t blow debris directly into an open spark plug well.

Step 3: Disconnect the electrical connector

• Press the release tab on the affected coil’s connector and pull the plastic connector straight back.
• Use the small flat-blade screwdriver only to gently help release a stubborn tab.
• Never pull on the wires. Old connector locks can be brittle.

Step 4: Remove the retaining bolt

• Use the 10mm socket, 3-inch extension, and 1/4-inch ratchet to remove the coil retaining bolt.
• Place the bolt somewhere secure so it cannot fall into the engine compartment.

Step 5: Remove the ignition coil

• Grip the coil body and gently rotate it a few degrees in each direction.
• Pull the coil straight upward out of the spark plug well.
• Don’t pry against the valve cover or wiring.
• Inspect the rubber boot for cracking, burning, carbon tracking, or oil contamination.
• If the spark plug well contains oil, stop and repair the valve-cover sealing problem before installing the coil.

Step 6: Inspect the spark plug well

• Use the compressed-air duster to clean around the well while the spark plug remains installed.
• Look for moisture, oil, corrosion, or a damaged coil connector.
• If the removed coil shows a white or black lightning-like line down its boot, the spark plug may also need inspection.

Step 7: Install the replacement coil

• Place a very small film of dielectric grease inside the opening of the new coil’s rubber boot.
• Dielectric grease is a silicone moisture barrier. Don’t pack the boot full of it.
• Align the coil with the spark plug well and push it straight down until fully seated.
• Align the coil’s mounting hole with the threaded hole in the valve cover.

Step 8: Install and tighten the retaining bolt

• Start the bolt by hand for several turns to prevent cross-threading.
• Use the inch-pound torque wrench and 10mm socket to tighten the bolt to 7 Nm (62 in-lbs).
• Don’t use a foot-pound wrench at this low setting. The small bolt and valve-cover mounting point are easily damaged.
• Snug is enough here. More isn’t better.

Step 9: Reconnect the coil

• Push the electrical connector onto the coil until its lock clicks.
• Gently pull on the connector housing to confirm it’s latched.
• Repeat Steps 3 through 9 for any additional coils being replaced.

Step 10: Reassemble the engine compartment

• If disconnected, reinstall the negative battery cable with the 10mm wrench and tighten it securely without crushing the terminal.
• Position the engine cover over its mounts and press down evenly until seated.
• Check that no tools, bolts, or loose connectors remain in the engine compartment.

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✅ After Repair

• 🚘 Start the engine and let it idle while listening for smooth, even operation.
• 🔍 Confirm that the check-engine light isn’t flashing and inspect for a loose connector.
• 📱 Use the OBD-II scan tool to clear the stored misfire code after recording it.
• 🛣️ Take a short, gentle test drive and rescan for pending misfire codes.
• ⚠️ If the same-cylinder misfire returns, inspect the spark plug, connector wiring, fuel injector, and cylinder compression rather than installing another coil blindly.

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💰 DIY vs Shop Cost

Shop Cost: $140-$350 for one coil, or approximately $350-$700 for four

DIY Cost: Approximately $39-$88 for one coil, or $156-$352 for four

You Save: Approximately $100-$350 by doing it yourself!

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

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🎯 Ready to get started?

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