Complete major tune-up service including spark plugs, air filter, cabin filter, engine oil and filter change, fluid inspection, and throttle body cleaning for the 2015 Kia Forte 1.8L I4 engine.

Warnings

Tools required

Parts

• Spark plugs (NGK or equivalent) × 4 — 18854-10060 or equivalent iridium plugs
• Engine oil filter × 1 — 26300-35503 or equivalent
• Engine air filter × 1 — 28113-2H000 or equivalent
• Cabin air filter × 1 — 97133-2H001 or equivalent
• Oil drain plug crush washer × 1 — 21513-23001

Fluids

• Kia Genuine 5W-20 — 4.5 qt

Preparation

1. Ensure engine is completely cold before beginning work
2. Park vehicle on level surface and engage parking brake
3. Gather all tools, parts, and fluids before starting
4. Place oil drain pan and rags within easy reach under engine area
5. Open hood and secure with prop rod

Procedure

1. 1

   Remove engine cover and air intake system
   Remove the plastic engine cover by pulling upward on the cover to disengage the rubber grommets. Disconnect the electrical connector from the mass airflow sensor. Loosen the air box clips and remove the intake air duct. Remove the air box assembly by releasing the clips and lifting upward to access the engine.
   Torque spec

   Air Box Clips5 Nm (4 lb-ft)
2. 2

   Replace engine air filter
   Open the air filter housing by releasing the clips on the side of the air box. Remove the old air filter and inspect the housing for debris. Clean housing if necessary with a dry cloth. Install the new air filter ensuring proper seating and orientation (arrows typically indicate airflow direction). Close and secure the housing clips.
3. 3

   Replace cabin air filter
   Open the glove box and remove contents. Locate the cabin air filter access panel behind the glove box. Remove the filter cover by pressing the tabs inward. Slide out the old cabin air filter noting the airflow direction arrows. Install the new cabin filter with arrows pointing in the correct direction (typically toward the blower motor). Reinstall the access cover.
4. 4

   Drain engine oil
   Position drain pan under the oil drain plug located on the driver's side of the oil pan. Using a 14mm socket, carefully loosen and remove the drain plug. Allow oil to drain completely for at least 5 minutes. Once drained, clean the drain plug and mating surface on the oil pan. Install a new crush washer on the drain plug and thread it in by hand before torquing.
   ⚠Hot oil can cause severe burns. Ensure engine is cold before draining.
   Torque spec

   Oil Drain Plug35 Nm (26 lb-ft)
5. 5

   Replace oil filter
   Locate the oil filter on the front of the engine block below the exhaust manifold. Position drain pan under the filter. Use an oil filter wrench to loosen and remove the old filter by turning counterclockwise. Clean the filter mounting surface on the engine block. Apply a thin film of clean engine oil to the rubber gasket of the new filter. Thread the new filter on by hand until the gasket contacts the mounting surface, then tighten an additional 3/4 to 1 full turn. Do not use a wrench to tighten.
6. 6

   Remove ignition coils
   Disconnect the electrical connectors from all four ignition coils by pressing the release tab and pulling straight up. Remove the single mounting bolt from each coil using a 10mm socket. Carefully pull each coil straight up and out of the spark plug well. Inspect the coil boots for cracks or damage.
   Torque spec

   Mounting Bolts26 Nm (19 lb-ft)
7. 7

   Remove and inspect old spark plugs
   Using a 16mm spark plug socket with extension, carefully remove each spark plug by turning counterclockwise. Keep plugs in order to identify which cylinder they came from. Inspect the electrode condition, gap wear, and deposits to assess engine condition. Check for oil fouling or abnormal wear patterns that might indicate engine issues.
8. 8

   Install new spark plugs
   Verify the spark plug gap on all new plugs is within specification (0.039-0.043 inches or 1.0-1.1 mm) using a gap tool. Apply a small amount of anti-seize compound to the threads (avoiding the electrode area). Thread each plug by hand into the cylinder head to avoid cross-threading. Once hand-tight, use the spark plug socket and torque wrench to tighten to 20-25 Nm (15-18 lb-ft). Note: While not in the torque spec list, manufacturer specification is 25 Nm; hand-tighten plus 1/4 turn is acceptable if torque wrench access is difficult.
9. 9

   Reinstall ignition coils
   Apply a small amount of dielectric grease to the inside of each coil boot. Carefully push each ignition coil down into its spark plug well until fully seated. Install the mounting bolt on each coil and torque to specification. Reconnect all four electrical connectors ensuring they click into place.
   Torque spec

   Mounting Bolts26 Nm (19 lb-ft)
10. 10

    Clean throttle body (optional but recommended)
    Locate the throttle body on the intake manifold. Disconnect the electrical connector and remove the air duct connection. Remove the throttle body mounting bolts using a 10mm socket. Spray throttle body cleaner on a clean rag and wipe the throttle plate and bore clean, being careful not to force the throttle plate. Reinstall using a new gasket if available, torquing bolts evenly in a cross pattern.
    Torque spec

    Sensor Bolts10 Nm (8 lb-ft)
11. 11

    Refill engine oil
    Remove the oil filler cap on top of the valve cover. Using a funnel, pour in 4.0 quarts of Kia Genuine 5W-20 engine oil initially. Wait 2 minutes for oil to settle, then check the dipstick. Add remaining oil in small increments until the level reaches the upper mark on the dipstick. Do not overfill. Install the oil filler cap securely.
12. 12

    Reinstall air intake system and engine cover
    Reinstall the air box assembly, ensuring it seats properly in the mounting grommets. Reconnect the air intake duct and secure all clips to specification. Reconnect the mass airflow sensor electrical connector. Reinstall the engine cover by aligning it with the mounting grommets and pressing down firmly until seated.
    Torque spec

    Air Box Clips5 Nm (4 lb-ft)
13. 13

    Start engine and verify operation
    Start the engine and allow it to idle. Check for any oil leaks around the oil filter and drain plug. Listen for any unusual noises or rough idle. The engine may run slightly rough for the first 30 seconds as the new spark plugs seat. Check the oil level once more after engine reaches operating temperature and top off if necessary. Verify no warning lights are illuminated on the dashboard.

Reassembly

1. Ensure all electrical connectors are fully seated and locked
2. Verify engine cover is properly installed and seated on all mounting grommets
3. Double-check that oil filler cap is securely tightened
4. Dispose of used oil, oil filter, and old parts according to local regulations

Verification

• Check engine oil level on dipstick with engine off and cold - level should be between MIN and MAX marks
• Start engine and verify smooth idle with no misfires or rough running
• Inspect underneath vehicle for any oil leaks from drain plug or filter after 5 minutes of operation
• Verify no warning lights (check engine, oil pressure) are illuminated
• Take vehicle for a short test drive and confirm smooth acceleration and no hesitation
• Recheck oil level after test drive and top off if necessary

More procedures for this vehicle