This procedure covers the replacement of spark plug wires on the 2015 Kia Forte 1.8L I4 engine, including removal of ignition coils and installation of new wires with proper routing.

Warnings

Tools required

Parts

• Spark plug wire set (4 wires) × 1 — Use OEM specification or equivalent ignition wire set

Preparation

1. Park vehicle on level surface and apply parking brake
2. Turn ignition off and remove key from ignition
3. Allow engine to cool for at least 30 minutes if recently operated
4. Open hood and secure with prop rod

Procedure

1. 1

   Remove engine cover
   Locate and remove the plastic engine cover by releasing the retaining clips. Gently pull upward on the cover to disengage the clips from the valve cover. Set the cover aside in a clean area.
   Torque spec

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

   Locate ignition coils and spark plug wires
   Identify all four ignition coils mounted on the valve cover. The 1.8L Nu engine uses individual coils for each cylinder. Note the position and routing of each spark plug wire from the coil to the spark plug.
   ℹ️Take a photo of wire routing for reference during installation
3. 3

   Remove first ignition coil
   Disconnect the electrical connector from ignition coil #1 (nearest to the timing belt end) by pressing the release tab and pulling straight up. Remove the single mounting bolt securing the coil using a 10mm socket. Carefully pull the coil straight up and out of the spark plug well.
   Torque spec

   Ignition Coil Bolt10 Nm (8 lb-ft)
4. 4

   Remove first spark plug wire
   Grasp the spark plug wire boot firmly at the base where it connects to the spark plug. Twist the boot slightly while pulling straight up to break the seal. Remove the wire from the spark plug. At the coil end, twist and pull the boot to disconnect. Clean any debris from around the spark plug well using compressed air or a wire brush.
   ⚠Never pull on the wire itself; always grasp and twist the boot to prevent internal wire damage
5. 5

   Install first new spark plug wire
   Apply a small amount of dielectric grease to the inside of both boots on the new wire. Connect one end to the spark plug, pushing firmly until you feel and hear a click. Connect the other end to the ignition coil in the same manner. Ensure the wire follows the original routing path and does not contact hot or moving engine components.
   ℹ️Wire must route away from exhaust manifold and accessory belts
6. 6

   Reinstall first ignition coil
   Insert the ignition coil back into the spark plug well, ensuring it seats fully onto the spark plug terminal. Install the mounting bolt and torque to specification. Reconnect the electrical connector until it clicks into place.
   Torque spec

   Ignition Coil Bolt10 Nm (8 lb-ft)
7. 7

   Replace remaining spark plug wires
   Repeat steps 3 through 6 for cylinders 2, 3, and 4, working one wire at a time. Move sequentially from cylinder 1 (timing belt end) to cylinder 4 (transmission end). This prevents mixing up the firing order. Verify each wire is properly seated at both ends before moving to the next cylinder.
   ⚠Replace only one wire at a time to maintain correct cylinder identification
   Torque spec

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

   Verify wire routing and clearances
   Inspect all four installed wires to ensure they follow the correct routing path without crossing each other. Verify adequate clearance from the exhaust manifold (minimum 1 inch), valve cover edges, and any moving components. Check that all wire retaining clips (if equipped) are properly engaged.
   ℹ️Improper routing can cause premature wire failure or cross-firing
9. 9

   Reinstall engine cover
   Position the engine cover over the valve cover, aligning the mounting clips with their receptacles. Press down firmly at each clip location until you hear them snap into place. Verify the cover is secure and seated evenly.
   Torque spec

   Engine Cover Clips3 Nm (2 lb-ft)

Reassembly

1. Double-check all electrical connectors are fully seated and locked
2. Verify no tools or parts are left in engine compartment
3. Ensure all ignition coil bolts are torqued to specification

Verification

• Start the engine and listen for smooth idle with no misfires or hesitation
• Rev engine to 2000 RPM and verify smooth operation without stumbling
• Check for any arcing or visible sparks around plug wires in darkness or with engine cover removed
• Scan for diagnostic trouble codes; no misfire codes (P0300-P0304) should be present
• Test drive vehicle to confirm normal acceleration and no check engine light

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