Every XA50 RAV4 — LE through TRD Off-Road, gas or hybrid — runs the same 2.5L A25A-FKS with coil-on-plug ignition, so the procedure is identical across the generation. It's a top-of-engine job: plastic cover off, intake duct moved aside, four 10 mm coil bolts, four long iridium plugs. The only real difference on hybrids is a more crowded bay and the need to make absolutely sure the hybrid system is off so the engine can't auto-start while your hands are in there.
The thing people get wrong is the socket. These are 14 mm hex plugs sitting in deep, narrow tubes — a generic 5/8 in plug socket won't go down, and a thick-wall 14 mm can bind and snap the insulator on removal. Buy a thin-wall magnetic plug socket before you start. The second mistake is torque: 13 ft-lb into an aluminum head feels far too loose, but guessing by feel is how threads get pulled.
| Item | Type | |
|---|---|---|
| Socket wrench set 3/8 in drive ratchet, 10 mm and 12 mm sockets Removes the engine cover studs, air duct clamp, coil bolts and battery terminal. | Required | shop |
| Extension bars 3/8 in drive, 3 in and 6 in Reaches the coil bolts and the deep spark plug tubes. | Required | shop |
| Trim removal tool set Plastic pry tools Pops the engine cover grommets and the plastic intake duct clips without breaking them. | Required | shop |
| Spark plug socket 14 mm thin-wall, magnetic or rubber insert, 3/8 in drive The A25A-FKS uses a 14 mm hex plug in a narrow tube; a standard 5/8 in socket will not fit. | Required | shop |
| Swivel / wobble extension 3/8 in drive wobble extension or short U-joint Helps clear the cowl and strut brace area on cylinder 4, especially on hybrids. | Recommended | shop |
| Torque wrench 3/8 in drive, 5-50 ft-lb range Iridium plugs thread into an aluminum head — overtightening strips it. | Required | shop |
| Compressed air or vacuum Air nozzle or shop vac with hose Blows dirt out of the plug wells so nothing falls into the cylinder. | Recommended | shop |
| Flashlight or inspection light LED work light Lets you see into the plug tubes and check coil boot condition. | Recommended | shop |
| Spark plug gap gauge Coin-type or wire gauge To verify factory gap only — do not bend iridium fine-wire tips. | Recommended | shop |
| Spark plugs Denso iridium long-life, OE type FC16HR-Q8 (Toyota 90919-01298) — confirm by VIN The correct heat range and reach for the A25A-FKS; four required. | Parts | shop |
| Dielectric grease Silicone dielectric compound, small tube Thin film inside the coil boots so they release next time; do not put it on the plug threads. | Consumables | shop |
| Anti-seize (optional, sparing) Nickel anti-seize Only if you choose to use it — a trace on the threads, never on the electrode, and reduce torque slightly. | Consumables | shop |
| Shop towels and brake cleaner Aerosol cleaner, lint-free towels Cleans oil and grit off the valve cover before opening the plug wells. | Consumables | shop |
| Safety glasses Debris falls out of plug wells when blowing them clean. | Safety | shop |
| Nitrile gloves Keeps oil off your hands and off the new plug insulators. | Safety | shop |
There is only one engine in this generation, the 2.5L A25A-FKS, in gas and hybrid form, so socket sizes are the same across all trims: 14 mm thin-wall plug socket and 10 mm coil bolts. Hybrid and Prime models simply have tighter access and require confirming the hybrid system is powered down before starting.
| Spark plug (M12 x 1.25, 14 mm hex, aluminum head) | 18 Nm (13 ft-lb) — verify in the service manual |
| Ignition coil hold-down bolt (10 mm head) | verify in the service manual (typically about 10 Nm / 7 ft-lb for Toyota coils) |
| 12V battery negative terminal nut | verify in the service manual (light, about 5 Nm) |
| Intake air duct clamp | verify in the service manual |
Coil bolts are 10 mm and the plug hex on the A25A-FKS is 14 mm (thin-wall socket needed), which I am confident about; confirm the exact plug part number by VIN at the parts counter and confirm plug and coil torque in the Toyota service information before final tightening.
Toyota specifies the factory iridium plugs at roughly 120,000 miles (about 192,000 km) under normal service. If the car does a lot of short trips, towing or idling, inspecting around 90,000 miles is reasonable.
A Denso long-life iridium plug, OE type FC16HR-Q8 (Toyota part number in the 90919-012xx family). Always confirm by VIN, and don't substitute a cheaper copper or platinum plug — the heat range and reach matter on this engine.
No. On the RAV4's A25A-FKS the coils and plugs are accessible from the top after removing the engine cover and swinging the plastic intake air duct out of the way.
A 14 mm thin-wall spark plug socket on a 3/8 in drive with a 6 in extension. The ignition coil hold-down bolts are 10 mm.