The spark plug socket size for a 2014 Honda Accord is typically 5/8 inch (16 mm) hex, a size that fits the majority of plugs used on the model's two main engines—the 2.4-liter inline-four and the 3.5-liter V6.
This article explains why that size is appropriate, outlines the two engines in that model year, and provides practical tool guidance and step-by-step instructions for safe plug replacement.
Engine options and plug configurations
The 2014 Accord came with two powertrains. Both use spark plugs compatible with a standard 5/8" socket, though coil layout and access differ slightly between engines.
2.4L inline-four (K-series)
In the 2.4L version, each cylinder uses a coil-on-plug arrangement and a standard 14mm spark plug with a 5/8" hex. Access is generally from the top of the engine, with individual coils removed to reach each plug. Follow the exact plug type and torque spec recommended by your plug manufacturer and Honda service data.
3.5L V6 (J-series)
The 3.5L V6 also uses coil-on-plug ignition with conventional 14mm plugs and a 5/8" hex. Access is more constrained by the engine bay layout, but the same socket size applies. Ensure you replace one plug at a time with intake/exhaust heat cycles considered, and torque to spec per the plug manufacturer.
Recommended spark plug socket size and tools
Before listing the tools, note that while 5/8" (16 mm) sockets are standard for Honda's 14mm plugs, some aftermarket or special plugs may use a 13/16" (21 mm) hex. If you encounter a plug with a larger hex, you may need the corresponding socket size. The following tools cover the common setup for the 2014 Accord:
- 5/8 inch (16 mm) spark plug socket with rubber insert and magnet
- 3/8 inch drive ratchet with a long extension (6–12 inches typically helps reach rear plugs)
- Optional: 13/16 inch (21 mm) spark plug socket if you encounter a larger hex plug
- Torque wrench to ensure proper seating according to the plug manufacturer or Honda service data
Using the correct socket reduces risk of damaging the spark plug or threads, and a magnetic, rubber-insert socket helps hold the plug during removal and installation. Do not apply anti-seize on Honda engines unless specified by the plug manufacturer; torque to the manufacturer’s specification rather than relying on feel.
Replacement procedure (high level)
Outlined here are general steps to replace spark plugs on a 2014 Accord. Always refer to the owner's manual or service manual for engine-specific instructions.
- Disconnect the negative battery terminal to avoid accidental short circuits.
- Remove any engine covers or intake components that block access to the coil packs.
- For each cylinder, disconnect the electrical connector for the coil-on-plug, and remove the coil or boot to expose the spark plug.
- Clean around the spark plug before loosening to prevent debris from entering the combustion chamber.
- Use the spark plug socket to loosen and remove the old plug, keeping the socket straight to avoid cross-threading.
- Check the gap on a replacement plug and adjust if required per the plug manufacturer’s specification.
- Install the new plug by hand to ensure clean threads, then tighten with a torque wrench to the recommended spec (usually around 13–21 ft-lb, depending on plug type—check the specific plug's data).
- Reinstall the coil/boot, reconnect any electrical connectors, and replace any components removed earlier.
- Reconnect the battery and start the engine to verify proper operation and absence of misfires.
Remember to perform the process engine-by-engine to avoid mixing components and to maintain proper torque and seating.
Notes and safety tips
Take your time, work in a clean, well-lit area, and wear eye protection. If the spark plugs have not been replaced for a long time, use anti-seize only if recommended by the plug manufacturer and Honda service data. If you are unsure about the spark plug type or torque specification for your exact vehicle, consult the official Honda service manual or a certified mechanic.
Summary
For a 2014 Honda Accord, a 5/8-inch (16 mm) spark plug socket is the standard choice for both the 2.4L I-4 and 3.5L V6 engines. Always verify your plug hex size on the replacement plugs, and follow the OEM torque specifications for safe, reliable performance. Proper tools and careful technique help prevent cross-threading and ensure a good seal for efficient combustion.