Replace spark plugs on a 2012-2017 Toyota Camry 2.5L I4 engine to restore proper ignition performance and fuel efficiency.

Warnings

Tools required

Parts

• Spark plugs × 4 — Use OEM specification - Toyota 90919-02260 or equivalent iridium plugs

Preparation

1. Ensure engine is completely cold to the touch
2. Park vehicle on level surface and engage parking brake
3. Gather all tools and new spark plugs
4. Verify new spark plugs match OEM specification for this engine

Procedure

1. 1

   Remove engine cover
   Grasp the engine cover firmly and pull upward to release the retaining clips. The cover is held by push clips only and does not require tools to remove. Set cover aside in a clean area.
2. 2

   Disconnect ignition coils
   Locate all four ignition coils positioned directly above each spark plug. Press down on the electrical connector tab and pull the connector straight off each coil. Mark or photograph coil positions if they appear different.
3. 3

   Remove ignition coil 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 up with a slight twisting motion to break the seal. The coil boots extend down into the spark plug wells. Inspect boots for cracks or tears and replace if damaged.
5. 5

   Clean spark plug wells
   Use compressed air or a clean lint-free rag to remove any debris from around the spark plug wells. Prevent any dirt or debris from falling into the cylinders during plug removal.
   ⚠Any debris that falls into the cylinder can cause serious engine damage
6. 6

   Remove old spark plugs
   Using a spark plug socket with extension, carefully loosen each spark plug by turning counterclockwise. Once loose, unthread by hand and remove. Inspect old plugs for unusual wear patterns, oil fouling, or damage which may indicate other engine issues.
7. 7

   Prepare new spark plugs
   Verify the gap on each new spark plug matches specification (typically 0.039-0.043 inches for this engine, confirm with plug manufacturer). Apply a small amount of anti-seize compound to the threads only, avoiding the electrode area. Use sparingly as excess can contaminate the plug.
   ⚠Do not allow anti-seize compound to contact the spark plug electrode or ground strap
8. 8

   Install new spark plugs
   Thread each new spark plug by hand into the cylinder head, ensuring it threads smoothly without cross-threading. Once hand-tight, use the torque wrench and spark plug socket to tighten to specification. Work carefully to avoid cross-threading in the aluminum head.
   ⚠️Cross-threading spark plugs in aluminum heads can destroy threads requiring expensive thread repair or cylinder head replacement
   Torque spec

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

   Apply dielectric grease to coil boots
   Apply a thin coat of dielectric grease to the inside of each ignition coil boot. This prevents moisture intrusion and makes future removal easier. Do not over-apply as excess grease can attract dirt.
10. 10

    Reinstall ignition coils
    Insert each ignition coil into its spark plug well, ensuring the coil boot seats fully onto the spark plug terminal. Push down firmly until you feel the coil seat against the valve cover. Install and torque the 10mm retaining bolt on each coil.
    Torque spec

    Ignition Coil Bolt11 Nm (8 lb-ft)
11. 11

    Reconnect electrical connectors
    Push each electrical connector onto its corresponding ignition coil until you hear or feel a positive click. Gently tug on each connector to verify it is fully seated and locked.
12. 12

    Reinstall engine cover
    Position the engine cover over the engine, aligning the retaining clips with their mounting points. Press down firmly on each clip location until you hear the clips snap into place.

Reassembly

1. Ensure all electrical connectors are fully seated and locked
2. Verify engine cover is securely clipped in place at all mounting points
3. Double-check that no tools or parts are left in the engine compartment

Verification

• Start the engine and verify it runs smoothly without misfires or rough idle
• Check for any fault codes using an OBD-II scanner
• Listen for any unusual noises that might indicate a coil not properly seated
• Verify the engine cover is secure and not vibrating
• Test drive the vehicle to confirm improved performance and no check engine light

More procedures for this vehicle