2003–2007 Honda Accord
By Ray Delgado ✓ Certified Mechanic · Published Sep 24, 2026 · Updated Oct 14, 2026
Save $251 by doing it yourself! Shop cost: $344
Quick answer: Spark Plug Replacement (V6) on a 2003–2007 Honda Accord is rated Moderate and takes about 1-1.5 hours. You'll need 6 tools for this job, and parts cost about $93. This guide walks you through the full job step by step, including the mistakes to avoid.
| Part Name | Part Number | Price | Buy |
|---|---|---|---|
| 6x NGK IZFR6K-11 laser iridium spark plugs | — | $83.00 | |
| Dielectric grease (for coil boots) | — | $10.00 |
About prices: shown prices are typical retail averages and change frequently; cheaper alternatives may be available. Confirm the current price before buying.
💡 Pro tip: Order all parts at once to save on shipping
Follow these steps carefully
Ensure your 2003-2007 Honda Accord V6 (J30A4 engine) is completely cold; working on a hot engine risks thread damage. Disconnect the negative battery terminal. Gather 6 NGK IZFR6K-11 laser iridium spark plugs (the OEM specification), a 5/8-inch spark plug socket, 3/8-inch ratchet with extensions, 10mm socket, and a torque wrench. Open the hood.
The J30A4 V6 has a plastic engine cover over the intake manifold. Remove the cover by unscrewing the fasteners or pulling up on the mounting grommets. This exposes the six ignition coils, three on each cylinder bank.
Start with the front bank for easier access. Each coil is secured by a 10mm bolt and has an electrical connector. Squeeze the connector tab and pull to disconnect. Remove the 10mm coil bolt, then pull the coil straight up and out of the plug well. Set coils aside in order. Inspect coil boots for cracks or carbon tracking.
Using a 5/8-inch spark plug socket with a 6-inch extension and 3/8-inch ratchet, loosen each spark plug by turning counterclockwise. Once loose, lift the plug out using the socket's rubber insert or a magnetic pickup. Inspect the old plugs for oil fouling, excessive gap wear, or damaged electrodes, which indicate other engine issues.
Quick word from someone who's been under there: I inspect the old plugs for oil fouling, gap wear, or damaged electrodes, which tell me about other engine issues.
Check the gap on each new NGK IZFR6K-11 plug; it should be pre-set to 0.044 inches (1.1mm) from the factory. Do not adjust iridium plugs as the fine electrode is easily damaged. Apply a small amount of anti-seize to the threads if desired (use sparingly). Carefully thread each plug in by hand to avoid cross-threading the aluminum head.
I've seen this exact mistake come through the shop: Do not adjust iridium plugs as the fine electrode is easily damaged.
Once hand-tight, use the torque wrench to tighten each spark plug to 13 ft-lbs (18 Nm). This is critical for the aluminum cylinder head; overtightening strips threads while undertightening causes poor heat transfer and potential blowout.
Small thing, big difference: I torque to exactly 13 ft-lbs on the aluminum head — I've seen overtightening strip threads and undertightening cause blowout.
Apply a dab of dielectric grease inside each coil boot to prevent moisture intrusion and ease future removal. Push each coil firmly onto its spark plug until seated. Reinstall the 10mm coil bolts and torque to 8 ft-lbs. Reconnect each electrical connector until it clicks. Double-check all six connections.
Reinstall the engine cover and reconnect the negative battery terminal. Start the engine and listen for smooth idle; a misfire indicates a loose coil or connector. Take a test drive to confirm proper acceleration.
Test your repair before closing everything up. If something doesn't work right, double-check your steps.
⚠️ Common Mistakes to Avoid
2003–2007
2003–2007
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