ignition

Spark Plugs - V8

for 2021 Toyota Camry 2.5L I4 · FWD

Difficulty

Easy

Time

2.0 h

Tools

Steps

🤖AI-generated, not yet human-verified. This walkthrough was produced by AI and may contain errors. Treat it as a guide, cross-check every step and torque value against the manufacturer's service manual, and stop if anything looks unsafe.

This procedure replaces the spark plugs on a 2018-2024 Toyota Camry with the 2.5L I4 engine. Note: This vehicle has a 4-cylinder engine, not a V8.

Warnings

⚠Perform this work with the engine completely cold to prevent thread damage and burns.

⚠This vehicle has an inline 4-cylinder engine, not a V8. The job title may be incorrect for this application.

ℹ️Over-torquing spark plugs in aluminum heads can cause thread damage requiring expensive repairs.

Tools required

10mm socketEssential

14mm spark plug socket with rubber insertEssential

3/8" drive ratchetEssential

6-inch extensionEssential

Torque wrench (5-30 Nm range)Essential

Spark plug gap toolEssential

Anti-seize compoundEssential

Dielectric grease

Compressed air or clean shop towels

Parts

Spark plugs × 4 — Toyota 90919-01253 or equivalent iridium plugs

Preparation

Ensure engine is completely cold (wait at least 2 hours after last operation)
Park vehicle on level surface and engage parking brake
Gather all tools and parts before beginning
Verify new spark plugs match OEM specifications (gap should be 0.043 inches / 1.1mm)
Disconnect negative battery terminal to prevent accidental starter engagement

Procedure

1
Remove engine cover
Grasp the engine cover firmly at the front corners and pull upward to release the clips. The cover is held by push clips only and requires no tools. Set aside in a clean area.
2
Remove ignition coils
Disconnect the electrical connector from each ignition coil by pressing the release tab and pulling straight up. Using a 10mm socket, remove the single bolt securing each ignition coil. Carefully pull each coil straight up from the spark plug well with a twisting motion to break the seal. Label or arrange coils in order (cylinder 1 is nearest the timing chain cover on passenger side) for proper reinstallation.
Torque spec
Ignition Coil Bolt11 Nm (8 lb-ft)
3
Clean spark plug wells
Use compressed air or clean shop towels to remove any debris, dirt, or oil from around the spark plug wells. This is critical to prevent contamination from falling into the cylinders when plugs are removed. If oil is present in the wells, inspect valve cover gasket condition.
⚠Any debris that falls into the cylinder can cause severe engine damage. Ensure wells are completely clean before removing plugs.
4
Remove old spark plugs
Using a 14mm spark plug socket with rubber insert and extension, carefully loosen each spark plug approximately one full turn. Verify no debris has fallen into wells, then completely unscrew and remove each plug. Inspect removed plugs for abnormal wear, oil fouling, or incorrect gap which may indicate other engine issues.
5
Gap and prepare new spark plugs
Using a spark plug gap tool, verify each new plug is gapped to 0.043 inches (1.1mm) per Toyota specification. Even pre-gapped plugs should be verified. Apply a small amount of anti-seize compound to the threads of each plug, coating approximately 2/3 of the thread length. Avoid getting anti-seize on the electrode or insulator.
ℹ️Use anti-seize sparingly. Excess compound can contaminate the electrode or cause incorrect torque readings.
6
Install new spark plugs
Carefully thread each new spark plug by hand into its cylinder, ensuring it threads smoothly without resistance. If you feel any binding, remove and restart - cross-threading will destroy the aluminum head. Once finger-tight, use the torque wrench and 14mm spark plug socket to tighten to specification. Torque all four plugs before proceeding.
⚠️Cross-threading spark plugs in the aluminum head will cause catastrophic damage requiring cylinder head repair or replacement. Always start threads by hand.
Torque spec
Spark Plug20 Nm (15 lb-ft)
7
Reinstall ignition coils
Apply a thin coat of dielectric grease to the inside of each ignition coil boot if desired (helps with future removal). Align each ignition coil with its corresponding spark plug and push down firmly until it seats completely. Install the 10mm retaining bolt and tighten to specification. Reconnect the electrical connector to each coil, ensuring it clicks securely into place.
Torque spec
Ignition Coil Bolt11 Nm (8 lb-ft)
8
Reinstall engine cover
Align the engine cover clips with their mounting points on the engine. Press down firmly at each clip location until you hear and feel each clip engage. Verify the cover is secure and sits flush.
9
Reconnect battery and clear codes
Reconnect the negative battery terminal. The vehicle may need to relearn idle and perform a calibration drive. If a check engine light appears, it may be a stored code from battery disconnection that will clear after a drive cycle.

Reassembly

Ensure all four ignition coil connectors are fully seated and locked
Verify engine cover is securely clipped at all mounting points
Double-check that no tools or parts were left in the engine bay

Verification

Start the engine and listen for smooth idle with no misfires or unusual sounds
Allow engine to reach operating temperature and verify no check engine light appears
Perform a test drive and confirm smooth acceleration with no hesitation or misfires under load
Visually inspect for any oil leaks around ignition coils after test drive
Use an OBD-II scanner to verify no misfire codes are present (P0300-P0304)