Complete cylinder head gasket replacement for 2015 Kia Forte 1.8L I4, including timing chain removal, head removal, surface preparation, and reassembly with new gasket and head bolts.

Warnings

Tools required

Parts

• Cylinder head gasket × 1 — Use OEM Kia specification
• Cylinder head bolts (TTY - must replace) × 1 — Set of 10 OEM head bolts
• Valve cover gasket × 1 — Use OEM specification
• Timing chain cover gasket × 1 — Use OEM specification
• Exhaust manifold gasket × 1 — Use OEM specification
• Intake manifold gasket × 1 — Use OEM specification
• Thermostat housing gasket/O-ring × 1 — Use OEM specification
• Spark plugs × 4 — OEM equivalent recommended
• Oil drain plug crush washer × 1 — Use OEM specification
• Engine oil filter × 1 — Use OEM specification
• Anti-seize compound × 1 — Nickel-based
• RTV silicone gasket maker × 1 — OEM or high-temp equivalent

Fluids

• Hyundai/Kia Long Life Coolant (Green) — 7.5 qt
• Kia Genuine 5W-20 Engine Oil — 4.5 qt

Preparation

1. Ensure engine is completely cold. Position vehicle on level surface and engage parking brake.
2. Disconnect negative battery terminal and wait 3 minutes for airbag system discharge.
3. Remove engine cover (pull upward on four mounting points).
4. Drain coolant by opening radiator drain plug and removing radiator cap slowly.
5. Drain engine oil and replace drain plug with new crush washer.
6. Remove air intake assembly from throttle body to air filter housing.
7. Label and disconnect all vacuum lines, electrical connectors, and fuel lines from intake manifold and cylinder head.
8. Relieve fuel system pressure by removing fuel pump fuse and cranking engine until it stalls.
9. Support engine from above using engine hoist or support fixture - engine will need to be lifted slightly.

Procedure

1. 1

   Remove accessory components and upper engine covers
   Remove ignition coils and spark plugs, labeling each cylinder position. Disconnect accelerator cable if equipped. Remove PCV hoses and breather hoses from valve cover. Disconnect engine harness connectors at head (cam position sensor, oil control valves). Tag all wiring for reinstallation.
2. 2

   Remove valve cover assembly
   Remove valve cover bolts in reverse of tightening sequence (outside to inside). Carefully lift valve cover off, breaking seal with plastic scraper if necessary. Inspect valve cover for cracks or warping. Remove and discard old gasket completely, cleaning all residue from mating surfaces.
3. 3

   Remove intake and exhaust manifolds
   Disconnect throttle body and fuel rail from intake manifold. Remove intake manifold bolts in reverse sequence and remove manifold with gasket. For exhaust manifold, disconnect oxygen sensor connector and remove heat shield. Remove exhaust manifold nuts working from cold end toward hot end (opposite of installation sequence). Remove manifold and gasket.
   ⚠Exhaust studs are prone to breaking on this engine. Apply penetrating oil 24 hours before removal if possible.
   Torque spec

   Intake Manifold Bolts25 Nm (18 lb-ft)

   Exhaust Manifold Nuts25 Nm (18 lb-ft)
4. 4

   Remove timing chain cover and set engine to TDC
   Remove accessory drive belts. Remove crankshaft pulley bolt (may require holding flywheel). Remove timing chain cover bolts and carefully pry cover off. Rotate crankshaft clockwise until timing marks on camshaft sprockets align with marks on chain guides AND crankshaft keyway points to 12 o'clock (cylinder 1 TDC compression stroke). Mark chain-to-sprocket relationship with paint marker.
   ⚠Verify both intake and exhaust cam timing marks are aligned. If only one aligns, rotate crankshaft one full additional revolution.
5. 5

   Remove timing chain tensioner and chain
   Remove timing chain tensioner bolt and extract tensioner assembly. Remove timing chain guides if needed for access. Hold exhaust camshaft with wrench on hex section and remove exhaust cam sprocket bolt. Hold intake camshaft and remove intake cam sprocket bolt. Remove both sprockets with chain as assembly, keeping chain engaged on sprockets. If chain must be separated, mark exact position on sprockets.
   ⚠️Do NOT rotate crankshaft or camshafts after chain removal. Wedge a clean rag in the chain cavity to prevent anything from falling into engine.
6. 6

   Remove camshaft bearing caps and camshafts
   Loosen camshaft bearing cap bolts in reverse sequence (outside to inside), in multiple passes to prevent warping. Remove bearing caps, keeping them in exact order and orientation. Carefully lift out intake and exhaust camshafts. Mark each camshaft for correct reinstallation. Inspect cam lobes and journals for scoring or wear.
   ⚠Bearing caps are directional and numbered. They MUST be reinstalled in exact original positions or engine damage will occur.
7. 7

   Remove cylinder head bolts and head
   Remove cylinder head bolts in reverse of tightening sequence (outside to inside). Loosen each bolt in multiple passes. Once all bolts are removed, discard them - they cannot be reused. Carefully break head seal using plastic pry points (never pry on sealing surfaces). Lift cylinder head straight up off block using assistance if needed - head weighs approximately 45 lbs. Place head on clean wooden blocks with combustion chambers facing up.
   ⚠️Old head bolts MUST be discarded. These are torque-to-yield bolts that permanently deform during installation and will fail if reused.
   Torque spec

   Cylinder Head Bolts - Step 140 Nm (30 lb-ft)
8. 8

   Inspect and clean mating surfaces
   Use plastic scraper to remove all old gasket material from block deck and cylinder head mating surface. Clean surfaces with brake cleaner and lint-free rags. Inspect block deck with straight edge in multiple directions - maximum warpage is 0.002 inches. Check cylinder head flatness similarly - if beyond spec, head must be machined. Inspect cylinders for scoring or damage. Verify all head bolt holes are clean and dry (use compressed air). Check for coolant or oil in cylinders.
   ⚠Never use metal scrapers on aluminum surfaces. Do not allow debris to fall into cylinders or oil passages.
9. 9

   Install new head gasket and position cylinder head
   Install new head gasket on block with TOP marking facing up and toward front of engine. Verify all alignment dowels are in place and gasket fits properly over them. Carefully lower cylinder head onto block, aligning with dowel pins. Ensure head seats completely on gasket with no interference. Install new cylinder head bolts finger-tight in correct positions.
   ⚠Head gasket orientation is critical - verify TOP marking and FRONT arrow before installation. Gasket cannot be reused if removed.
10. 10

    Torque cylinder head bolts in sequence
    Following manufacturer's tightening sequence (start at center, work outward in spiral pattern): Step 1 - Torque all bolts to 40 Nm (30 lb-ft). Step 2 - Torque all bolts to 80 Nm (59 lb-ft) in same sequence. Step 3 - Using angle gauge, rotate each bolt an additional 90 degrees in same sequence. Mark bolts with paint to verify 90-degree rotation. Do not skip or combine steps.
    ⚠️Head bolt torque sequence and angle-tightening MUST be followed exactly. Incorrect torque or sequence will cause head gasket failure and possible engine damage.
11. 11

    Reinstall camshafts and bearing caps
    Lubricate camshaft journals and lobes with clean engine oil. Install intake and exhaust camshafts in correct positions with timing marks positioned for TDC (marks should face outward). Install bearing caps in exact original positions with arrows pointing toward intake side. Tighten bearing cap bolts in sequence from center outward, in 3 passes, to final torque of 14 Nm (10 lb-ft). Verify camshafts rotate smoothly by hand.
    ⚠Camshaft timing must be correct before installing chain. Verify timing marks are in TDC position before proceeding.
12. 12

    Install timing chain, sprockets, and tensioner
    Install timing chain onto camshaft sprockets in exact marked positions from removal. Install sprocket and chain assembly onto camshafts, aligning timing marks. Hold intake camshaft on hex and install sprocket bolt to 80 Nm (59 lb-ft). Hold exhaust camshaft and torque sprocket bolt to 80 Nm (59 lb-ft). Install timing chain guides if removed. Compress timing chain tensioner and install locking pin/clip. Install tensioner and torque bolt to 25 Nm (18 lb-ft). Remove tensioner pin to apply tension. Rotate crankshaft 2 complete revolutions clockwise and verify all timing marks realign perfectly.
    ⚠️Timing marks MUST align after 2 complete crankshaft rotations. If timing is off, valve-to-piston contact will occur causing catastrophic engine damage.
13. 13

    Install timing cover and reassemble external components
    Clean timing cover and block mating surfaces. Apply thin bead of RTV silicone to cover as specified in service manual. Install timing cover and bolts, tightening evenly. Install crankshaft pulley. Install exhaust manifold with new gasket, applying anti-seize to studs, torquing nuts to 30 Nm (22 lb-ft) working from hot end to cold end. Install intake manifold with new gasket, torquing bolts in sequence to 25 Nm (18 lb-ft).
    Torque spec

    Exhaust Manifold Nuts25 Nm (18 lb-ft)

    Intake Manifold Bolts25 Nm (18 lb-ft)
14. 14

    Install valve cover and final components
    Install new valve cover gasket in cover groove. Clean valve cover mating surface on head. Position valve cover and install bolts finger-tight. Torque valve cover bolts in sequence from center outward to 10 Nm (7 lb-ft). Reconnect all electrical connectors, vacuum lines, and fuel lines per labels. Install new spark plugs to proper gap and torque. Install ignition coils. Reinstall PCV and breather hoses. Install air intake assembly.
15. 15

    Refill fluids and initial startup
    Install new oil filter and fill engine with 4.5 quarts of Kia Genuine 5W-20 oil. Close cooling system drains and fill with 7.5 quarts of Hyundai/Kia Long Life Green coolant mixture (50/50 with distilled water). Reconnect battery negative terminal. Turn ignition to ON position (don't start) and check for fuel leaks. Crank engine for 5 seconds to build oil pressure. Start engine and check immediately for oil pressure light to extinguish and for any leaks. Allow engine to warm to operating temperature while monitoring for leaks, unusual noises, or overheating. Bleed cooling system by running engine with radiator cap off until thermostat opens and air bubbles stop.
    ⚠Do not rev engine during initial startup. Allow oil pressure to build and circulate before increasing RPM above idle.

Reassembly

1. Reassembly is detailed in steps 9-15 above. Key points: Use all new gaskets, seals, and TTY head bolts. Follow all torque specifications and sequences exactly. Verify timing chain alignment before and after installation.
2. Double-check all electrical connectors, vacuum hoses, and fluid levels before final startup.
3. After initial startup and warm-up, recheck all fasteners for proper torque, especially valve cover and manifolds which may need retorquing after first heat cycle.

Verification

• Check engine oil level on dipstick and verify no leaks from oil pan, filter, or valve cover.
• Verify coolant level is correct and cooling system has no leaks. Check that thermostat is operating (upper radiator hose should get hot).
• Confirm no fuel, vacuum, or exhaust leaks around manifolds and connections.
• Engine should idle smoothly with no unusual noises, vibrations, or misfires. Check for diagnostic trouble codes.
• Verify proper oil pressure at idle and operating temperature (should be above 20 PSI at hot idle).
• Test drive vehicle after reaching operating temperature - check for normal power, no overheating, and no warning lights.
• After 50-100 miles, recheck oil and coolant levels. Inspect for any new leaks. Consider retorquing valve cover if seepage appears.

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