2019 Honda Odyssey - Spark Plug Type & Gap

Quick reference

Why the right plug matters

Choosing the correct spark plug for your 2019 Honda Odyssey is more critical than you might think. Spark plugs are not "one size fits all" components. They are engineered to precise specifications, including heat range, electrode material, and gap, all of which directly impact engine performance, fuel economy, and emissions.

Heat Range: This refers to the plug's ability to dissipate heat. A "cold" plug dissipates heat quickly and is used in high-performance engines to prevent pre-ignition. A "hot" plug retains heat and is used in engines that operate at lower temperatures. Using a plug with an incorrect heat range can lead to issues like fouling (too cold) or overheating and pre-ignition (too hot), both of which can damage your engine.

Electrode Metal: Modern engines, like your Odyssey's 3.5L V6, typically come from the factory with iridium or platinum spark plugs. These "precious metal" plugs offer superior durability and conductivity compared to traditional copper plugs.

• Iridium: The hardest and most corrosion-resistant of the spark plug materials, iridium allows for very fine electrodes that produce a strong, focused spark. This leads to better fuel efficiency and emissions, along with extended service intervals – often exceeding 100,000 miles.
• Platinum: While not as durable as iridium, platinum plugs still offer significant advantages over copper, including better longevity and performance. They are often used as an OEM choice for their balance of performance and cost.
• Copper: Though not typically found in modern engines as original equipment, copper plugs have excellent conductivity. However, their softer material wears more quickly, necessitating much shorter replacement intervals.

How to gap a spark plug

While many modern iridium and platinum spark plugs come pre-gapped from the factory, it's always a good practice to verify the gap before installation. Even a slight jolt during shipping can alter the gap. For your 2019 Honda Odyssey with the 3.5L V6 engine, the correct gap is 0.044 inches (1.1 mm).

To gap a spark plug, you'll need a wire gauge tool. Avoid using a coin-style gapping tool, as it can damage the delicate iridium or platinum electrode. Gently slide the appropriate wire gauge between the center and ground electrodes. If the gap is too small, carefully bend the ground electrode outwards with the gapping tool's adjuster. If it's too wide, carefully tap the ground electrode on a hard, non-abrasive surface to close the gap. Always ensure the ground electrode remains parallel to the center electrode.

Replacement procedure tips

Replacing the spark plugs in your 2019 Honda Odyssey's 3.5L V6 engine can be a DIY project for those comfortable with basic automotive maintenance. Here are some tips to ensure a smooth process:

1. Cool Engine: Always work on a cool engine. Attempting to remove spark plugs from a hot engine can increase the risk of damaging the cylinder head threads.
2. Access: The Honda J-series V6 engine in your Odyssey has spark plugs located under the intake manifold for the rear bank (cylinders 1, 2, 3). This will require removing the intake manifold to access them. The front bank (cylinders 4, 5, 6) is more easily accessible.
3. Coil-on-Plug Removal: Your Odyssey uses a coil-on-plug (COP) ignition system. Each spark plug has its own individual ignition coil. Carefully disconnect the electrical connector from each coil and then unbolt the coil. Pull the coil straight up to remove it. Avoid twisting or prying, which can damage the coil boot.
4. Anti-Seize Debate: There is ongoing debate about using anti-seize compound on spark plug threads. For spark plugs with a nickel-plated shell (which most modern plugs are), manufacturers like NGK generally advise against using anti-seize. The nickel plating provides sufficient corrosion protection, and anti-seize can act as an insulator, altering torque readings and potentially leading to over-tightening and plug damage or stripping the cylinder head threads. Follow the spark plug manufacturer's specific recommendations.
5. Dielectric Grease: Apply a small amount of dielectric grease to the inside of the spark plug boot (the end that connects to the spark plug). This helps to seal out moisture, prevents corrosion, and makes future removal easier.
6. Torque Wrench: Always use a torque wrench to tighten the new spark plugs to the manufacturer's specification of 13 lb-ft (18 Nm). Over-tightening can damage the spark plug or the cylinder head threads, while under-tightening can lead to combustion gas leaks and plug overheating.

Known issues

The 2019 Honda Odyssey's 3.5L V6 engine (J35Y6) is generally reliable, and there are no widespread "known issues" specifically related to spark plug breakage or unique challenges like those seen in some Ford 3-valve engines with two-piece plugs. As long as you use the correct spark plugs and follow the recommended replacement procedures, you should have no problems.

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