2018 Toyota RAV4 Spark Plug Replacement Guide — Step-by-Step

The 2018 Toyota RAV4 with the 2.5L 2AR-FE naturally aspirated four-cylinder is one of the most straightforward spark plug jobs I've done on a crossover. Four plugs, top-access, no plenum removal required. If you've been putting this off because it sounds complicated, it isn't — budget 45–60 minutes and you're done.

The key specs: iridium plugs rated for long-life intervals, 13 ft-lbs torque (don't over-torque — aluminum head), and correct coil-on-plug reinstallation to avoid misfires.

Engine: 2.5L 2AR-FE 4-Cylinder

• OEM plug: Denso SK20HR11 (iridium) — factory-installed long-life plug
• Equivalent NGK: ILFR6A or ILZKR7B-11 (NGK Laser Iridium)
• Gap: 0.043" (1.1mm) — pre-set on iridium plugs; do not regap
• Torque: 13 ft-lbs (18 Nm)
• Service interval: 60,000 miles (iridium long-life spec per Toyota)
• Plug thread size: M14×1.25

Why Iridium Plugs Are Not Negotiable Here

The 2AR-FE's ignition system is designed around iridium-tipped plugs. Copper plugs will work as a temporary measure but require replacement every 20,000–30,000 miles and can introduce misfires at higher mileage. For a $40–$60 set of iridium plugs that last 60,000 miles, there's no reason to compromise.

Do not gap iridium plugs. The iridium electrode is extremely brittle — any attempt to adjust the gap will break or chip it.

What You'll Need

• 4× Denso SK20HR11 or NGK ILFR6A iridium plugs
• 5/8" spark plug socket (with rubber insert — essential for iridium)
• 3/8" ratchet with 6" and 3" extensions
• Torque wrench
• 10mm socket (COP bolt)
• Compressed air or vacuum
• Dielectric grease

Step-by-Step Procedure

Preparation:

1. Park on a level surface and let the engine cool — at least 2 hours.
2. Remove the engine cover if equipped.
3. Blow out each plug well with compressed air.

Remove Coil-On-Plug (COP) Units: 4. Disconnect the electrical connector on each COP — press the release tab and pull straight back. Do one at a time. 5. Remove the 10mm COP bolt. Pull the COP straight up — rotate slightly if the boot sticks.

Remove Old Plugs: 6. Insert the spark plug socket into the plug well. 7. Break the plug loose counter-clockwise — old iridium plugs at 60,000 miles will be snug but shouldn't require excessive force. 8. Spin out the rest of the way by hand. 9. Inspect each plug: Light tan/gray electrode = healthy. Black sooty = rich/oil burning. White/chalky = lean/overheating.

Install New Plugs: 10. Do not apply anti-seize to iridium plugs — the nickel coating on the shell provides adequate lubrication. 11. Thread each plug in by hand — all the way until the seat contacts the head. If you meet resistance before the seat, back out and realign. 12. Torque each plug to 13 ft-lbs (18 Nm). Trust the spec — don't add "a little more for security."

Reinstall COPs: 13. Apply a small amount of dielectric grease to the inside of the COP boot. 14. Push each COP straight down until it seats on the plug. 15. Install the 10mm COP bolt — approximately 80 in-lbs (9 Nm). 16. Reconnect each electrical connector — press until you hear the click. 17. Reinstall the engine cover. 18. Start the engine — should fire immediately and idle smoothly.

Cost Comparison: DIY vs. Dealer

	DIY	Toyota Dealer
4× Denso iridium plugs	$35–$50	Included
Labor	$0	$100–$150
Total	$35–$50	$150–$220

For more Toyota RAV4 maintenance guides including oil changes, brake service, and battery replacement, browse the OwnerDrop blog.

Get the full guide + every torque spec in the OwnerDrop library — OwnerDrop /pricing.