Tools you need for spark plugs on a 2013-2017 Honda Accord

On the 2.4L K24W four-cylinder this is one of the easiest 100k-mile services on the car. Cover off, four coils out with a 10 mm socket, four plugs out with a 5/8 in thin-wall socket on an extension, done in under an hour with basic hand tools.

The 3.5L V6 is a different story. Three plugs sit under the upper intake manifold, so you are pulling the plenum, hoses and connectors to reach them, which is why shops charge two to three times as much. The mistake people make on both engines is skipping the torque wrench: these heads are aluminum, the spec is only 13 ft-lb, and gorilla-tightening a plug or adding anti-seize is how threads get pulled. Blow the plug wells out before the socket goes in, too.

Complete tool and parts list

Differences within the 2013-2017 generation

Both engines use the same 5/8 in (16 mm) thin-wall plug socket, 10 mm coil bolts and 13 ft-lb plug torque. The difference is access and plug count: the 2.4L K24W has four plugs, all on top and fully accessible; the 3.5L J35Y has six, and the rear three require removing the upper intake manifold (add 10 mm and 12 mm sockets, hose clamp pliers and a plenum gasket set). Plug part numbers also differ between the two engines, so order by engine, not just by year.

Torque specs

How the job goes

1. Work on a cold engine. Disconnect the negative battery terminal (10 mm) if you want to clear adaptations; it is not strictly required, but note the radio presets.
2. 2.4L: remove the plastic engine cover (pull the decorative cover off its grommets / remove the retaining nuts), then unclip the wiring harness running across the valve cover.
3. 2.4L: press the lock tab and unplug each of the four ignition coil connectors, then remove the single 10 mm bolt holding each coil and pull the coils straight up with a twisting motion.
4. Blow out each plug well with compressed air or vacuum it before the socket goes in, so nothing falls into the cylinder.
5. Break each plug loose with the 5/8 in thin-wall socket, extension and ratchet. Loosen a half turn, then back it out. If a plug feels gritty, back it out and blow the well out again.
6. Compare new plugs to old; confirm the gap gauge reads about 0.043 in (1.1 mm). Do not bend the tip of an iridium plug and do not use anti-seize.
7. Start each new plug by hand or with the socket and extension only (no ratchet) until it seats, then torque to 13 ft-lb (18 Nm). Never force a cross-threaded plug in an aluminum head.
8. Wipe a thin film of dielectric grease inside each coil boot, reinstall the coils, torque the bolts to 87 in-lb (9.8 Nm) and click the connectors back on until they lock.
9. 3.5L V6 front bank (plugs 1-3 on the radiator side): remove the engine cover and the front three coils the same way, then replace those plugs.
10. 3.5L V6 rear bank: remove the intake air duct/resonator and throttle body air hose, unplug the throttle body and MAP/sensor connectors, disconnect the PCV and brake booster vacuum hoses and any coolant hoses at the plenum, then unbolt the upper intake manifold (plenum) and its support brackets and lift it off. Cover the open intake ports with clean rags.
11. With the plenum off, remove the three rear coils, blow out the wells and replace plugs 4-6 at 13 ft-lb.
12. Reinstall the V6 plenum with new or good gaskets, torque the bolts in a criss-cross pattern from the center outward per the service manual, and reconnect every hose, connector and ground strap you removed.
13. Reconnect the battery, start the engine and let it idle. Confirm no misfire, no vacuum leak whistle on the V6, and no check-engine light; drive a few miles and recheck.

Watch out

The 5/8 in plug socket, 10 mm coil bolts, 13 ft-lb plug torque and 1.1 mm gap are well established for both the K24W and J35Y in this generation; verify the V6 upper intake manifold bolt torque and sequence in a factory service manual before reassembly.

Other jobs on the 2013-2017 Honda Accord

Spark Plug Replacement on other vehicles