This procedure covers removal, machine shop resurfacing, and reinstallation of the cylinder head on the 2.5L I4 engine, including valve train disassembly and timing system reinstallation.

Warnings

Tools required

Parts

• Cylinder head gasket × 1 — Use OEM Hyundai/Kia gasket
• Valve cover gasket × 1 — Use OEM specification
• Exhaust manifold gasket × 1 — Use OEM specification
• Intake manifold gasket × 1 — Use OEM specification
• Timing chain guide × 1 — Inspect and replace if worn
• Timing chain tensioner gasket × 1 — Use OEM specification
• Camshaft seals × 2 — Front seals for intake/exhaust cams
• Cylinder head bolts × 10 — TTY bolts - must replace
• Spark plugs × 4 — OEM recommended plugs
• Engine oil × 5 — Hyundai Genuine 0W-20
• Oil filter × 1 — Use OEM filter
• Anti-seize compound × 1 — Nickel-based for exhaust studs

Fluids

• Hyundai/Kia Long Life Coolant (Green) — 10 qt
• Hyundai Genuine 0W-20 — 5 qt

Preparation

1. Ensure engine is completely cold (minimum 4 hours after last operation)
2. Disconnect negative battery terminal and wait 3 minutes for airbag system discharge
3. Drain engine coolant completely into appropriate container using radiator drain plug and lower hose
4. Remove engine cover by pulling upward on front clips and releasing rear fasteners
5. Remove intake air duct and air filter housing assembly
6. Relieve fuel system pressure by removing fuel pump fuse and cranking engine until it stalls
7. Label and photograph all vacuum lines, electrical connectors, and hose routing for reassembly reference
8. Support engine from above using hoist with load leveler or install engine support fixture across fender rails

Procedure

1. 1

   Remove accessory components and upper engine parts
   Disconnect throttle body electrical connector and remove throttle body. Disconnect fuel line quick-connect at fuel rail using appropriate tool. Remove ignition coils and spark plugs, labeling cylinder positions. Disconnect all engine harness connectors from cylinder head area including injectors, camshaft sensors, and coolant temperature sensors. Remove PCV hoses and breather tubes from valve cover.
2. 2

   Remove valve cover
   Remove valve cover bolts in reverse of tightening sequence (work from outside toward center). Carefully lift valve cover off cylinder head. If stuck, gently tap with rubber mallet - do not pry between sealing surfaces. Remove and discard valve cover gasket. Clean any oil residue from spark plug tubes.
   Torque spec

   Cover Bolts16 Nm (12 lb-ft)
3. 3

   Remove intake and exhaust manifolds
   Disconnect exhaust pipe from exhaust manifold at flange connection. Remove intake manifold bolts in reverse sequence (outside to inside) and lift manifold away, disconnecting any remaining vacuum lines. Remove exhaust manifold heat shields. Remove exhaust manifold nuts working from center (hot) toward ends (cold) as specified. Keep all hardware organized by component.
   ⚠Exhaust manifold studs are fragile. If any break, they must be extracted before head can be removed.
   Torque spec

   Intake Manifold Bolts25 Nm (18 lb-ft)

   Exhaust Manifold Nuts30 Nm (22 lb-ft)
4. 4

   Set engine to TDC and mark timing positions
   Rotate crankshaft clockwise using harmonic balancer bolt until cylinder #1 is at TDC compression stroke (both cam lobes pointing away from each other). Mark timing chain position relative to camshaft sprockets using paint marker. Mark crankshaft sprocket and chain position. Take multiple reference photos. Verify timing marks on camshaft sprockets align with cylinder head timing marks.
   ⚠️Incorrect timing marks will result in valve-to-piston contact and catastrophic engine damage upon reassembly.
5. 5

   Remove timing chain components from cylinder head
   Install camshaft holding tool to lock camshafts in position. Remove timing chain upper guide mounting bolts. Compress timing chain tensioner and lock in compressed position using pin or suitable tool, then remove tensioner mounting bolts. Remove camshaft sprocket bolts while holding camshafts with holding tool. Do NOT allow camshafts to rotate. Carefully lift timing chain off camshaft sprockets and support chain with wire to prevent it from falling into timing cover.
   ⚠Do not allow timing chain to fall into timing cover. Secure chain to prevent rotation of crankshaft sprocket.
   Torque spec

   Mounting Bolts47 Nm (35 lb-ft)
6. 6

   Remove camshafts and rocker assembly
   Loosen camshaft bearing cap bolts gradually in reverse sequence (outside to inside), no more than 1/4 turn at a time to prevent warping. Remove bearing caps keeping them in order - they are directional and position-specific. Lift camshafts from cylinder head and store in clean area. Remove rocker arms and lash adjusters, keeping them organized by cylinder position for reinstallation in original locations.
   ⚠Camshaft bearing caps must be reinstalled in exact original positions and orientation. Mark or photograph before removal.
7. 7

   Remove cylinder head bolts and head
   Loosen cylinder head bolts gradually in reverse of tightening sequence (work from outside toward center). Loosen each bolt 1/4 turn in sequence, then repeat until all bolts are loose. Remove all cylinder head bolts completely and discard - these are TTY bolts and cannot be reused. Carefully break cylinder head seal by gently prying at designated pry points only (check service manual for locations). Lift cylinder head straight up off block. Place head gasket-side-up on clean workbench covered with clean shop towels.
   ⚠Never pry between head and block sealing surfaces. Use only designated pry points to prevent warping.
   Torque spec

   Cylinder Head Bolts65 Nm (48 lb-ft)
8. 8

   Inspect and prepare block surface
   Stuff clean shop rags into all cylinder bores and coolant passages to prevent debris entry. Using plastic scraper only, carefully remove all gasket material from engine block deck surface. Clean surface thoroughly with appropriate solvent. Remove rags from cylinders. Inspect block deck with straightedge and feeler gauge - warpage should not exceed 0.002 inches (0.05mm). Check cylinder head bolt holes for thread damage and clean with thread chaser if needed. Verify no coolant or oil in bolt holes.
9. 9

   Transport cylinder head to machine shop
   Transport cylinder head to qualified machine shop for inspection and resurfacing. Shop should check for cracks using dye penetrant or magnetic particle testing, measure head flatness, resurface deck if needed (not to exceed 0.008 inches / 0.20mm total removal), perform valve job including seat cutting and lapping, pressure test for cracks, clean all carbon deposits, and measure valve stem height after grinding. Request valve spring pressure testing if head showed signs of overheating.
   ℹ️Provide machine shop with vehicle specifications. Over-milling can cause valve-to-piston contact and require shimming or thicker head gasket.
10. 10

    Prepare cylinder head for installation
    Inspect resurfaced cylinder head. Verify all valve springs installed correctly, valve stem seals in place, and all machining debris removed. Clean cylinder head deck surface with clean lint-free cloth and brake cleaner. Verify all bolt holes in head are clean and dry. Install new camshaft seals if removed during machining. Verify rocker arms and lash adjusters were kept organized - these must return to original positions.
11. 11

    Install new head gasket and cylinder head
    Final clean of engine block deck surface with brake cleaner and lint-free cloth. Position new cylinder head gasket on block with all alignment dowels properly seated - verify 'TOP' or 'FRONT' marking faces up and toward front of engine. Carefully lower cylinder head onto block, aligning over dowel pins. Install NEW cylinder head bolts finger-tight in sequence. Following manufacturer sequence diagram, torque head bolts in three stages: Stage 1 - torque all bolts to 65 Nm (48 lb-ft) in sequence, Stage 2 - tighten an additional 90 degrees in sequence using angle gauge, Stage 3 - tighten final 90 degrees in sequence.
    ⚠️Head bolt tightening sequence and angle torque procedure is critical. Failure to follow exactly will result in head gasket failure.
    Torque spec

    Cylinder Head Bolts65 Nm (48 lb-ft)
12. 12

    Reinstall camshafts and rocker assembly
    Lubricate all rocker arms and lash adjusters with clean engine oil. Install rocker arms and lash adjusters in their original positions on cylinder head. Apply clean engine oil to all camshaft bearing journals and lobes. Position camshafts in cylinder head with timing marks facing upward. Install camshaft bearing caps in original positions and orientation - caps are marked with numbers and directional arrows. Torque bearing cap bolts gradually in sequence from inside to outside, 1/4 turn at a time until reaching specified torque to prevent camshaft binding.
13. 13

    Reinstall timing chain and components
    Verify crankshaft is still at TDC position. Remove wire support from timing chain. Align timing chain on camshaft sprockets according to marks made during disassembly and install sprockets on camshafts. Verify all timing marks align correctly - camshaft marks on sprockets to head marks, chain colored links to sprocket marks. Install camshaft sprocket bolts using camshaft holding tool and torque to specification. Install timing chain upper guide and torque mounting bolts. Release timing chain tensioner lock pin and install tensioner, torquing mounting bolts to specification. Verify timing marks still aligned after tensioner release.
    ⚠️Triple-check all timing marks before proceeding. Rotate engine 2 full revolutions by hand and verify marks realign at TDC.
    Torque spec

    Mounting Bolts47 Nm (35 lb-ft)
14. 14

    Install manifolds with new gaskets
    Apply anti-seize compound to exhaust manifold stud threads as specified. Position new exhaust manifold gasket and install exhaust manifold. Torque exhaust manifold nuts working from center (hottest area) toward ends (cooler areas) to specification. Install exhaust manifold heat shields. Position new intake manifold gasket and install intake manifold. Torque intake manifold bolts in proper sequence (inside to outside pattern) to specification. Reconnect exhaust pipe to exhaust manifold with new gasket.
    Torque spec

    Exhaust Manifold Nuts30 Nm (22 lb-ft)

    Intake Manifold Bolts25 Nm (18 lb-ft)
15. 15

    Install valve cover and remaining components
    Install new valve cover gasket in valve cover groove - ensure gasket is fully seated. Apply small dab of RTV sealant at camshaft cap joints as specified in service manual. Position valve cover on cylinder head and install bolts finger-tight. Following sequence diagram (work from inside to outside), torque valve cover bolts to specification. Install new spark plugs torqued to specification. Install ignition coils. Reconnect all electrical connectors, vacuum lines, and hoses per photos and labels. Install throttle body with new gasket if needed. Reconnect fuel line. Install air filter housing and intake duct. Install engine cover.
    Torque spec

    Cover Bolts16 Nm (12 lb-ft)

    Sensor Bolts11 Nm (8 lb-ft)

Reassembly

1. Refill cooling system with specified Hyundai/Kia Long Life Coolant, bleeding all air from system using bleed valve on thermostat housing
2. Refill engine with correct quantity of Hyundai Genuine 0W-20 oil and install new oil filter
3. Reconnect negative battery terminal
4. Prime fuel system by cycling ignition on/off 3-4 times without cranking before first start attempt

Verification

• Start engine and verify no coolant, oil, or fuel leaks at all connection points and gasket surfaces
• Check for proper engine idle quality - should be smooth with no misfires or rough running
• Verify no unusual noises from valve train - ticking, knocking, or rattling indicates improper assembly
• Allow engine to reach full operating temperature and verify cooling fan cycles normally
• Check coolant level after engine cools - top off if needed and verify no leaks
• After test drive, re-check all fluid levels and inspect for any new leaks
• Perform cylinder leak-down test if available to verify proper valve sealing after head work
• Clear any diagnostic codes and verify no check engine light or timing-related codes present

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