maintenance
90K Service
for 2015 Kia Forte 1.8L I4 · FWD
Difficulty
Moderate
Time
4.0 h
Tools
14
Steps
14
Complete 90,000 mile scheduled maintenance service including fluid changes, filter replacements, and comprehensive inspection of critical components.
Warnings
⚠️Never work under a vehicle supported only by a jack. Always use jack stands rated for the vehicle weight.
⚠️Engine oil and coolant are extremely hot when at operating temperature. Allow engine to cool for at least 2 hours before beginning service.
⚠Wear nitrile gloves when handling used engine oil and transmission fluid as prolonged skin contact can cause irritation.
⚠Do not mix different types or brands of coolant. Use only Hyundai/Kia Long Life Coolant (Green) for this vehicle.
ℹ️The 2015 Forte 1.8L does not require timing belt service as it uses a timing chain. Spark plug replacement interval is 90k miles.
Tools required
Floor jack and jack standsEssential
Wheel chocksEssential
Oil drain pan (10+ quart capacity)Essential
Funnel setEssential
Oil filter wrenchEssential
Socket set (8mm-19mm)Essential
Combination wrench setEssential
Torx bit set (T20-T30)
Flathead screwdriver
Pliers
Tire pressure gaugeEssential
Inspection light
Coolant hydrometer or refractometer
Brake fluid tester
Parts
- Engine oil filter × 1 — 26300-35503 or equivalent
- Engine air filter × 1 — 28113-2H000 or equivalent
- Cabin air filter × 1 — 97133-2H001 or equivalent
- Drain plug washer × 1 — 21513-23001 or equivalent
- Spark plugs (set of 4) × 4 — 18855-10080 or NGK/Denso equivalent
Fluids
- Kia Genuine 5W-20 engine oil — 4.5 qt
- Kia SP-IV-M ATF (if servicing transmission) — 3 qt
- DOT 4 Brake Fluid (if flushing) — 1 qt
- Hyundai/Kia Long Life Coolant (Green) — 1 qt
Preparation
- Park vehicle on level surface and apply parking brake firmly
- Place wheel chocks behind rear wheels
- Ensure engine is completely cold before starting work
- Gather all required fluids, filters, and tools
- Start engine and allow to idle for 2 minutes to warm fluids slightly for easier draining, then shut off and wait 10 minutes
- Raise front of vehicle with floor jack and secure on jack stands at designated jacking points
- Remove engine splash shield/undertray if equipped (multiple clips and fasteners)
Procedure
- 1Drain engine oilPosition drain pan under oil pan drain plug. Remove drain plug using appropriate socket (typically 17mm) and allow oil to drain completely for at least 10 minutes. Inspect drain plug threads and washer for damage. Replace drain plug washer with new one and reinstall drain plug hand-tight, then snug (do not overtighten).
- 2Replace engine oil filterLocate oil filter on front-left side of engine block below intake manifold. Using oil filter wrench, turn filter counterclockwise to remove. Clean filter mounting surface on engine block. Apply thin film of clean engine oil to rubber gasket of new filter. Hand-tighten new filter clockwise until gasket contacts mounting surface, then turn an additional 3/4 to 1 full turn. Do not use filter wrench to tighten.
- 3Refill engine oil and verify levelRemove oil filler cap on top of engine. Using funnel, add 4.0 quarts of Kia Genuine 5W-20 oil initially. Wait 2 minutes for oil to settle, then check dipstick. Add remaining oil in small increments until level reaches upper mark on dipstick. Install oil filler cap. Start engine and let idle for 1 minute, checking for leaks at filter and drain plug. Shut off engine, wait 5 minutes, and recheck oil level. Adjust as necessary.
- 4Replace engine air filterOpen hood and locate air filter housing on driver's side of engine bay. Release clips securing air filter housing cover (typically 4-6 clips). Lift cover and remove old air filter element. Inspect housing for debris and clean if necessary. Install new air filter ensuring proper orientation and seating. Secure housing cover with all clips.
- 5Replace cabin air filterOpen glove box and remove contents. Press inward on both sides of glove box to release stops and lower glove box fully. Locate cabin air filter cover on right side of HVAC housing. Press tabs to release cover and pull out old filter, noting airflow direction arrow. Install new cabin air filter with airflow arrow pointing in same direction (toward rear of vehicle). Reinstall cover and reset glove box stops.
- 6Replace spark plugsLocate ignition coil pack assemblies on top of valve cover (4 coils). Disconnect electrical connector from each coil by pressing release tab. Remove coil mounting bolt (10mm) from each coil and carefully pull coils straight up. Use compressed air to blow out any debris from spark plug wells. Remove spark plugs using spark plug socket (16mm). Inspect old plugs for wear patterns. Check gap on new plugs (should be 0.039-0.043 inches). Apply small amount of anti-seize to plug threads (avoid electrode area). Hand-thread new plugs, then tighten to finger-tight plus 1/16 turn (approximately 15-20 lb-ft). Reinstall ignition coils and reconnect electrical connectors.
- 7Inspect and top off coolantWith engine cold, check coolant level in overflow reservoir located on driver's side of engine bay. Level should be between MIN and MAX marks. If low, remove radiator cap slowly to release any residual pressure, then add Hyundai/Kia Long Life Coolant (Green) as needed. Check coolant concentration with hydrometer; should be 50/50 mix for -35°F protection. Inspect all coolant hoses for cracks, swelling, or leaks. Reinstall radiator cap securely.
- 8Inspect brake fluid and systemCheck brake fluid level in master cylinder reservoir located on driver's side firewall. Fluid should be between MIN and MAX marks. Inspect fluid color; DOT 4 brake fluid should be clear to light amber. Dark or contaminated fluid indicates need for complete system flush. Check for leaks at master cylinder, brake lines, and calipers. Test brake pedal feel with engine running; should be firm with no sinking.
- 9Inspect transmission fluid (if applicable)For vehicles with automatic transmission, locate transmission dipstick near rear of engine bay (some 2015 models may not have serviceable transmission). With engine at operating temperature and on level ground, check fluid level and condition. Fluid should be bright red and smell sweet. Dark brown or burnt-smelling fluid indicates need for service. Top off with Kia SP-IV-M ATF if low. Note: Complete transmission drain and fill requires dropping transmission pan.
- 10Inspect belts and hosesVisually inspect serpentine drive belt for cracks, glazing, fraying, or missing ribs. Check belt tension by pressing on belt midway between pulleys; should have approximately 1/4 inch deflection. Inspect all accessible coolant hoses, vacuum lines, and breather hoses for cracks, hardening, or leaks. Check battery cables and terminals for corrosion or looseness.
- 11Inspect suspension and steering componentsWith vehicle raised, inspect all four struts/shocks for leaks or damage. Check ball joints and tie rod ends for excessive play or torn boots. Inspect CV axle boots for tears or grease leakage. Check steering rack boots for damage. Inspect all suspension bushings for cracking or deterioration. Verify no unusual wear patterns on steering and suspension mounting points.
- 12Inspect brake componentsRemove all four wheels. Measure brake pad thickness at all four corners; minimum thickness is 3mm (pads should be replaced if at or below 4mm). Inspect brake rotors for scoring, excessive rust, or warping. Check brake hoses for cracking, bulging, or leaks. Verify caliper slide pins move freely and boots are intact. Reinstall wheels and torque lug nuts to factory specification (approximately 80 lb-ft in star pattern).
- 13Check tire condition and pressuresInspect all four tires for tread depth using penny test (minimum 4/32 inch recommended). Check for uneven wear patterns indicating alignment issues. Look for cuts, bulges, or embedded objects. Set all tire pressures to specification listed on driver's door jamb placard (typically 33 PSI front and rear when cold). Don't forget to check spare tire pressure.
- 14Perform final system checksLower vehicle from jack stands. Check operation of all exterior lights (headlights, turn signals, brake lights, reverse lights). Test windshield wipers and washer fluid spray pattern; top off washer fluid if needed. Check HVAC system operation at all fan speeds. Verify horn functions properly. Test all power windows and door locks. Check that parking brake holds vehicle on incline.
Reassembly
- Reinstall engine splash shield/undertray with all clips and fasteners
- Double-check that all fluid caps are securely tightened (oil filler, coolant reservoir, brake fluid, etc.)
- Verify oil filter and drain plug are secure with no leaks
- Ensure all electrical connectors are fully seated and latched
- Confirm all wheels are properly torqued and hubcaps/center caps reinstalled if applicable
Verification
- Start engine and verify no warning lights remain illuminated on instrument cluster
- Listen for unusual noises from engine bay during idle and light acceleration
- Check under vehicle for any fluid leaks after engine has run for 5 minutes
- Verify oil pressure gauge shows normal reading (if equipped)
- Test drive vehicle for 10-15 minutes, checking transmission shifts, brake operation, and steering response
- Recheck all fluid levels after test drive and top off if necessary
- Reset maintenance reminder light if equipped using trip odometer reset procedure in owner's manual
- Document all service performed including mileage, date, and any issues found for vehicle maintenance records