This procedure covers the inspection and replacement of spark plug wires on the 2019-2024 Toyota RAV4 2.5L I4 gas engine, though this engine uses individual coil-on-plug ignition without traditional plug wires.

Warnings

Tools required

Parts

• Spark plugs × 4 — 90919-01253 (Denso IXUH22I) or equivalent iridium

Preparation

1. Ensure engine is completely cool to the touch
2. Park vehicle on level surface and engage parking brake
3. Disconnect negative battery terminal and wait 3 minutes for airbag system to discharge
4. Locate all four ignition coils on top of the engine

Procedure

1. 1

   Remove engine cover if equipped
   If your RAV4 has a plastic engine cover, carefully pull upward on the cover to release the retaining clips. Some models may have bolts securing the cover - remove these first using the appropriate socket.
   Torque spec

   Engine Cover Clips3 Nm (2 lb-ft)
2. 2

   Disconnect ignition coil electrical connectors
   Locate the electrical connector on each of the four ignition coils. Press the release tab on each connector and pull straight up to disconnect. Note the orientation and routing of each connector for reassembly.
   ℹ️Each connector may have a secondary lock that must be released before pressing the main tab.
3. 3

   Remove ignition coil mounting bolts
   Using a 10mm socket, remove the single bolt securing each ignition coil to the valve cover. Keep bolts organized as they will be reused.
   Torque spec

   Ignition Coil Bolt11 Nm (8 lb-ft)
4. 4

   Extract ignition coils
   Grasp each ignition coil firmly and pull straight upward with a twisting motion to break the seal. The coil boots are seated in the spark plug wells and may require moderate force to remove. Inspect each coil boot for cracks, tears, or carbon tracking.
   ⚠Do not pry against the coil body as this may crack the plastic housing. Use only pulling force.
5. 5

   Clean spark plug wells
   Use compressed air to blow out any debris, dirt, or oil from each spark plug well. Ensure the area around each spark plug is completely clean before removal to prevent contamination from entering the combustion chamber.
   ⚠If oil is present in the spark plug wells, this indicates a valve cover gasket leak that should be addressed separately.
6. 6

   Remove spark plugs
   Using the spark plug socket with extension, carefully loosen each spark plug by turning counterclockwise. Once loose, unscrew by hand to prevent cross-threading. Remove all four plugs and inspect electrodes for wear, fouling, or abnormal deposits.
   ℹ️Normal electrode wear shows a light tan or gray color. Black sooty deposits indicate rich mixture, white deposits indicate lean mixture.
7. 7

   Gap new spark plugs
   Using a spark plug gap tool, verify each new spark plug is gapped to 0.039-0.043 inches (1.0-1.1mm) per Toyota specifications. Adjust if necessary by carefully bending the ground electrode. Never gap iridium plugs more than once.
   Torque spec

   Spark Plug20 Nm (15 lb-ft)
8. 8

   Apply anti-seize and install spark plugs
   Apply a thin coating of anti-seize compound to the threads of each new spark plug, avoiding the first two threads and keeping compound away from the electrode area. Thread each plug into its cylinder by hand, turning clockwise until finger-tight to ensure proper threading.
   ⚠Cross-threading a spark plug in the aluminum cylinder head will require expensive thread repair. Always start by hand.
   Torque spec

   Spark Plug20 Nm (15 lb-ft)
9. 9

   Torque spark plugs to specification
   Using a torque wrench with spark plug socket, tighten each spark plug to exactly 20 Nm (15 lb-ft). Do not over-torque as this can damage the aluminum threads in the cylinder head.
   Torque spec

   Spark Plug20 Nm (15 lb-ft)
10. 10

    Reinstall ignition coils
    Apply a small amount of dielectric grease to the inside of each coil boot. Align each ignition coil with its corresponding spark plug and press down firmly until the coil is fully seated on the valve cover. The coil should sit flush with no gaps.
    ℹ️You should feel the coil boot click onto the spark plug terminal when properly seated.
11. 11

    Install and torque coil bolts
    Install the mounting bolt for each ignition coil and torque to 8 Nm (6 lb-ft) using a torque wrench. Do not over-tighten as the valve cover is plastic.
    Torque spec

    Ignition Coil Bolt11 Nm (8 lb-ft)
12. 12

    Reconnect electrical connectors
    Reconnect the electrical connector to each ignition coil, pressing firmly until you hear and feel a click. Verify each connector is fully locked by gently pulling on it.
13. 13

    Reinstall engine cover
    If removed, align the engine cover with its mounting points and press down firmly to engage all clips, or install and torque any mounting bolts to specification.
    Torque spec

    Engine Cover Clips3 Nm (2 lb-ft)

Reassembly

1. Reconnect the negative battery terminal
2. Ensure all tools and parts are removed from the engine bay
3. Verify all electrical connectors are properly secured

Verification

• Start the engine and listen for smooth operation with no misfires or rough idle
• Check for any diagnostic trouble codes using an OBD-II scanner - there should be no ignition-related codes
• Verify no vacuum leaks by listening for hissing sounds around the coils and plugs
• Test drive the vehicle to confirm smooth acceleration and no hesitation under load
• After initial test drive, allow engine to cool and visually inspect for any oil leaks around spark plug wells

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