This procedure covers the removal and replacement of all four spark plugs on the 2012-2017 Toyota Camry 2.5L I4 engine, including ignition coil removal and reinstallation.

Warnings

Tools required

Parts

• Spark plug (iridium) × 4 — Toyota 90919-01253 or Denso SK20R11

Preparation

1. Ensure engine is completely cool to the touch
2. Park vehicle on level surface and engage parking brake
3. Open hood and secure with prop rod
4. Verify you have the correct spark plugs for this application (iridium, pre-gapped to 0.043" / 1.1mm)

Procedure

1. 1

   Remove engine cover
   The plastic engine cover is held by clips and possibly screws. Grasp the cover firmly and pull upward to release the clips. If equipped with screws, remove them first with a 10mm socket before lifting the cover.
   Torque spec

   Cover Screws11 Nm (8 lb-ft)

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

   Disconnect ignition coil connectors
   Locate all four ignition coils mounted directly on top of the spark plugs. Press the locking tab on each electrical connector and pull straight up to disconnect. Do not pull on the wiring harness itself.
   ℹ️Mark or photograph connector positions if concerned about proper reinstallation order, though they are identical.
3. 3

   Remove ignition coil bolts
   Each ignition coil is secured by a single 10mm bolt. Remove all four bolts and keep them organized. Note that the coil on cylinder #1 (driver's side, closest to timing belt) may have limited clearance.
   Torque spec

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

   Remove ignition coils
   Grasp each ignition coil firmly and pull straight up with a gentle twisting motion. The coils fit snugly into the spark plug wells. Once removed, inspect the coil boot for cracks, tears, or oil contamination. Set coils aside in order on a clean work surface.
5. 5

   Clean spark plug wells
   Use compressed air or a vacuum to remove any debris, dirt, or oil from the spark plug wells. This is critical to prevent contamination from falling into the combustion chamber when spark plugs are removed.
   ⚠Ensure all debris is removed before loosening spark plugs to prevent foreign material from entering the cylinders.
6. 6

   Remove old spark plugs
   Using the 5/8" spark plug socket with extension, carefully loosen each spark plug by turning counterclockwise. Once loose, unthread by hand to prevent cross-threading. Remove all four plugs and inspect for abnormal wear, oil fouling, or excessive carbon buildup which may indicate engine issues.
   ℹ️Normal spark plug color is light tan to gray. Black sooty deposits indicate rich mixture, white indicates lean mixture, and oil on threads indicates valve cover gasket issues.
7. 7

   Prepare new spark plugs
   Verify the gap on all new spark plugs using a gap tool; factory spec is 0.043" (1.1mm). Even pre-gapped plugs should be checked. If using anti-seize compound, apply a very small amount to only the first 2-3 threads. Avoid getting anti-seize on the electrode area.
   ⚠Excessive anti-seize can cause over-torquing and thread damage. Use sparingly or omit entirely as modern plugs have anti-corrosion plating.
8. 8

   Install new spark plugs
   Thread each spark plug by hand into the cylinder head, turning clockwise until finger-tight. This ensures proper alignment and prevents cross-threading. Use the spark plug socket and extension to seat each plug, then torque to specification using the torque wrench.
   ⚠️Never force a spark plug. If resistance is felt before finger-tight, remove and restart to avoid cross-threading the aluminum head.
   Torque spec

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

   Apply dielectric grease to coil boots
   If desired, apply a small amount of dielectric grease to the inside of each ignition coil boot. This helps prevent moisture intrusion and makes future removal easier. Wipe away any excess.
   ℹ️Dielectric grease is optional but recommended for long-term corrosion protection in humid climates.
10. 10

    Reinstall ignition coils
    Align each ignition coil with its spark plug and press down firmly until fully seated. The coil should sit flush with the valve cover surface. Install the 10mm mounting bolt for each coil and torque to specification.
    Torque spec

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

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

    Reinstall engine cover
    Position the engine cover over the mounting points and press down firmly on all clip locations until seated. If equipped with screws, install and torque to specification. Ensure the cover sits evenly and is not binding on any components.
    Torque spec

    Cover Screws11 Nm (8 lb-ft)

    Engine Cover Clips3 Nm (2 lb-ft)

Reassembly

1. Ensure all electrical connectors are fully seated and locked
2. Verify engine cover is properly secured and not interfering with any components
3. Double-check that no tools or parts were left in the engine bay

Verification

• Start the engine and verify it runs smoothly without misfires or rough idle
• Check for diagnostic trouble codes using an OBD-II scanner; there should be no misfire codes (P0300-P0304)
• Listen for any abnormal sounds such as ticking or arcing from the ignition coils
• Allow engine to reach operating temperature and verify smooth operation at idle and during light acceleration
• Inspect around ignition coils for any signs of arcing or unusual electrical discharge

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