Replace spark plugs on the 1.5L turbocharged engine to restore ignition performance and fuel efficiency.

Warnings

Tools required

Parts

• Spark plugs (NGK DILKAR7G11GS or equivalent) × 4 — NGK 94870 or Honda OEM

Preparation

1. Ensure engine is completely cold to prevent burns and allow proper torque specifications
2. Park vehicle on level surface and engage parking brake
3. Open hood and ensure adequate workspace around engine bay

Procedure

1. 1

   Remove engine cover
   Grasp the engine cover firmly at multiple points and pull upward to release the retaining clips. The cover uses push-clip fasteners and does not require tools for removal. Set cover aside in clean area.
   Torque spec

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

   Locate ignition coils
   Identify all four ignition coils mounted directly on top of the cylinder head. Each coil has an electrical connector on top and is secured by a single 10mm bolt. Note the coil positions (cylinders numbered 1-4 from timing belt end).
3. 3

   Disconnect ignition coil connectors
   Press the locking tab on each coil connector and pull straight up to disconnect. Work gently to avoid damaging the connector clips. Leave connectors positioned where they won't fall into engine bay.
4. 4

   Remove ignition coil bolts
   Using a 10mm socket, remove the single bolt securing each ignition coil. Keep bolts organized and clean. The coils are now ready to extract.
   Torque spec

   Ignition Coil Bolt10 Nm (8 lb-ft)
5. 5

   Extract ignition coils
   Carefully pull each ignition coil straight up and out of the spark plug tube. Use a slight twisting motion if resistance is felt, but do not force. Inspect rubber boot at bottom of each coil for cracks or deterioration. Set coils in order on clean surface.
   ℹ️Ignition coil boots may stick in spark plug tubes due to heat cycling. Gentle twisting helps break the seal.
6. 6

   Clean spark plug wells
   Use compressed air or shop vacuum to remove any debris, oil, or dirt from around the spark plugs and inside the plug tubes. This prevents contamination from falling into cylinders during plug removal. Inspect for oil pooling which may indicate valve cover gasket issues.
7. 7

   Remove old spark plugs
   Using a spark plug socket with extension, carefully loosen each spark plug by turning counterclockwise. Once loose, remove by hand to prevent cross-threading. Inspect old plugs for unusual wear, oil fouling, or electrode damage which may indicate engine issues.
   ⚠If plugs are extremely difficult to remove, apply penetrating oil and wait before attempting further removal to avoid thread damage.
8. 8

   Prepare new spark plugs
   Remove new spark plugs from packaging. Using gap tool, verify each plug is gapped to 0.028-0.031 inches (0.7-0.8mm) per Honda specification. The iridium plugs come pre-gapped but should be verified. If using anti-seize, apply a very small amount only to the first 2-3 threads (optional on this aluminum head).
   ℹ️Excessive anti-seize can affect torque readings and cause over-tightening. Use sparingly or omit entirely.
9. 9

   Install new spark plugs
   Carefully thread each new spark plug by hand into the cylinder head, turning clockwise. Ensure plugs thread smoothly without resistance. If any binding is felt, remove and restart to avoid cross-threading. Thread each plug until finger-tight, then use torque wrench to tighten to specification.
   ⚠️Cross-threading spark plugs in aluminum head requires expensive head repair. Always start by hand and ensure smooth threading.
   Torque spec

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

    Apply dielectric grease to coil boots
    Apply a small amount of dielectric grease to the inside of each ignition coil boot. This prevents moisture intrusion, aids future removal, and ensures good electrical contact with spark plug terminal.
11. 11

    Reinstall ignition coils
    Insert each ignition coil straight down into its spark plug tube, ensuring the boot seats fully onto the spark plug terminal. Push firmly until coil sits flush against valve cover. Align mounting bolt hole.
    ℹ️Coil must seat completely on spark plug. Incomplete seating causes misfires and poor engine performance.
12. 12

    Install ignition coil bolts
    Install and hand-tighten each coil mounting bolt. Using torque wrench, tighten bolts to specification. Do not over-tighten as this can crack the coil housing.
    Torque spec

    Ignition Coil Bolt10 Nm (8 lb-ft)
13. 13

    Reconnect electrical connectors
    Push each electrical connector firmly onto its corresponding ignition coil until the locking tab clicks into place. Verify secure connection by gently tugging on each connector.
14. 14

    Reinstall engine cover
    Align engine cover clips with their mounting grommets on the engine. Press down firmly at each clip location until all clips fully engage with an audible click. Verify cover is secure and seated evenly.
    Torque spec

    Engine Cover Clips3 Nm (2 lb-ft)

Reassembly

1. Ensure all electrical connectors are fully seated and locked before starting engine
2. Verify no tools or parts were left in engine bay
3. Double-check that engine cover is properly secured at all clip points

Verification

• Start engine and verify smooth idle with no misfires or rough running
• Check for check engine light or flashing MIL which would indicate misfire
• Listen for any unusual clicking or arcing sounds from ignition coils
• Test drive vehicle to confirm normal acceleration and no hesitation under load
• Scan for diagnostic trouble codes if any performance issues are noted

More procedures for this vehicle