Complete removal and reinstallation of the cylinder head on the 2.5L I4 engine, including timing chain components, camshafts, and valve train assembly.

Warnings

Tools required

Parts

• Cylinder head gasket × 1 — Use OEM specification
• Cylinder head bolts (TTY) × 1 — Use OEM specification - not reusable
• Valve cover gasket × 1 — Use OEM specification
• Timing cover gasket/seal × 1 — Use OEM specification
• Intake manifold gasket × 1 — Use OEM specification
• Exhaust manifold gasket × 1 — Use OEM specification
• Thermostat housing gasket/O-ring × 1 — Use OEM specification
• Oil drain plug crush washer × 1 — Use OEM specification
• Engine coolant × 1 — Hyundai/Kia Long Life Coolant (Green)
• Engine oil and filter × 1 — Hyundai Genuine 0W-20
• Anti-seize compound × 1 — Nickel-based, high temperature

Fluids

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

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery cable and wait 3 minutes for airbag system discharge
3. Remove engine cover and plastic under-tray panels
4. Drain engine coolant completely into appropriate container by opening radiator petcock and removing lower radiator hose
5. Drain engine oil and replace drain plug with new crush washer
6. Remove front engine mount and install engine support fixture to support engine weight
7. Remove air intake duct and air filter housing assembly
8. Label and photograph all vacuum lines, electrical connectors, and coolant hoses for reinstallation reference

Procedure

1. 1

   Remove valve cover and accessory components
   Disconnect ignition coil connectors and remove all four ignition coils. Remove PCV hose and breather hose from valve cover. Remove valve cover bolts in reverse of tightening sequence (outside to inside pattern). Carefully lift valve cover off, tapping gently with rubber mallet if stuck. Remove any remaining gasket material from valve cover mating surface.
   Torque spec

   Cover Bolts16 Nm (12 lb-ft)
2. 2

   Remove intake and exhaust manifolds
   Disconnect throttle body electrical connector and all fuel injector connectors. Release fuel system pressure by removing fuel pump fuse and cranking engine briefly. Disconnect fuel supply line using quick-disconnect tool. Remove intake manifold bolts working from outside to inside, then lift manifold clear. For exhaust manifold, spray penetrating oil on nuts and allow to soak. Remove oxygen sensor. Remove exhaust manifold heat shield. Remove exhaust manifold nuts working from cold side (furthest from turbo port) to hot side to minimize warping. Lift exhaust manifold away.
   Torque spec

   Intake Manifold Bolts25 Nm (18 lb-ft)

   Exhaust Manifold Nuts30 Nm (22 lb-ft)
3. 3

   Remove timing chain cover
   Remove drive belt by rotating tensioner counterclockwise and sliding belt off pulleys. Remove crankshaft pulley bolt (use breaker bar with vehicle in gear or holder tool to prevent rotation). Remove water pump pulley. Disconnect crankshaft position sensor and camshaft position sensors. Remove timing chain cover bolts following reverse sequence pattern (remove outer bolts first, then inner). Gently pry cover loose using plastic pry tool at designated pry points - do not damage sealing surfaces. Clean all gasket material from cover and block mating surfaces.
   Torque spec

   Cover Bolts16 Nm (12 lb-ft)

   Sensor Bolts11 Nm (8 lb-ft)
4. 4

   Lock timing chain and mark positions
   Rotate crankshaft clockwise until No. 1 piston is at TDC on compression stroke (both camshaft lobes for cylinder 1 pointing outward, timing marks aligned). Verify crankshaft keyway is at 12 o'clock position. Mark timing chain position relative to camshaft sprockets using paint pen. Install timing chain locking tool or wedge to prevent chain movement. Take multiple reference photos showing exact chain position on all sprockets.
   ⚠Triple-check timing marks before proceeding. Incorrect timing will destroy engine on startup.
5. 5

   Remove camshaft components
   Hold intake camshaft with wrench on hex section and remove camshaft sprocket bolt. Carefully remove sprocket while keeping timing chain supported - do not allow chain to fall into engine. Repeat for exhaust camshaft sprocket. Install timing chain keeper tool or wire to suspend chain. Mark camshaft bearing caps with cylinder number and position (intake/exhaust). Remove camshaft bearing cap bolts in reverse sequence (outside to inside, multiple passes to release valve spring pressure evenly). Carefully lift camshafts out and store in clean area where they cannot roll.
   ⚠Loosen bearing cap bolts gradually in multiple passes. Uneven loosening can warp camshafts or damage bearing caps.
   Torque spec

   Camshaft Sprocket Bolt80 Nm (59 lb-ft)

   Camshaft Bearing Cap Bolts14 Nm (10 lb-ft)
6. 6

   Remove cylinder head
   Disconnect all remaining coolant hoses from cylinder head including heater hoses and thermostat housing connections. Remove thermostat housing completely. Disconnect engine wiring harness from cylinder head (coolant temperature sensor, knock sensor if accessible). Loosen cylinder head bolts in reverse of tightening sequence (outside to inside pattern) in multiple passes. Remove all cylinder head bolts and set aside - these must be replaced with new TTY bolts. Carefully lift cylinder head straight up off block - use assistance as head weighs approximately 50 lbs. If head is stuck, gently tap with rubber mallet at designated lift points - never pry between head and block gasket surfaces.
   ⚠Cylinder head is heavy and awkward. Use proper lifting technique or get assistance to avoid injury or dropping the head.
   Torque spec

   Cylinder Head Bolts65 Nm (48 lb-ft)

   Thermostat Housing Bolts15 Nm (11 lb-ft)
7. 7

   Inspect and prepare cylinder head
   Place cylinder head on clean wooden blocks with combustion chambers facing up. Inspect head for cracks, especially between valve seats and in coolant passages. Check head surface flatness with precision straightedge and feeler gauge - maximum warpage allowed is 0.05mm. If resurfacing is needed, take to machine shop (maximum material removal 0.20mm). Clean all carbon deposits from combustion chambers. Verify all valves seat properly and valve stem seals are intact if head is being reused. Clean head gasket surface thoroughly with plastic scraper - surface must be completely clean and smooth.
   ℹ️If cylinder head is warped beyond specification, it must be resurfaced by qualified machine shop or replaced.
8. 8

   Prepare engine block and install new head gasket
   Stuff clean shop rags into cylinder bores to prevent debris from falling in. Clean cylinder block gasket surface meticulously using plastic scraper and solvent - no old gasket material or oil can remain. Remove rags from cylinders and wipe bores clean. Inspect block deck surface for damage. Verify all coolant and oil passages in block are clean and clear. Position new cylinder head gasket on block - gasket will only fit one way with alignment dowels. Verify gasket part number matches application and that 'TOP' or 'OBEN' mark faces up. Do not use any sealant on head gasket.
   ⚠Ensure no debris falls into cylinders during cleaning. Even small particles can score cylinder walls or damage pistons.
9. 9

   Install cylinder head
   Carefully lower cylinder head onto block, aligning with dowel pins. Head must sit flush with no gaps around gasket perimeter. Install new TTY cylinder head bolts finger-tight in sequence. Using torque wrench, tighten all head bolts to 65 Nm (48 lb-ft) in sequence following factory diagram (typically inside to outside pattern). After all bolts reach initial torque, tighten each bolt an additional 90 degrees (1/4 turn) in same sequence. Finally, tighten each bolt another 90 degrees (total 180 degrees angle from torque spec) in sequence. Verify all bolts have been angle-tightened properly.
   ⚠️Must use new TTY head bolts. Old bolts are permanently stretched and will fail. Follow torque sequence exactly as specified.
   Torque spec

   Cylinder Head Bolts65 Nm (48 lb-ft)
10. 10

    Install timing chain tensioner and guides
    Inspect timing chain guides for wear grooves or damage - replace if worn beyond 1mm depth. Install new or inspected chain guides and tighten bolts to specification. Compress timing chain tensioner fully and lock with retaining pin or clip. Install tensioner and tighten mounting bolt. Verify tensioner is locked in compressed position and will release when pin is removed.
    Torque spec

    Timing Chain Guide Bolts12 Nm (9 lb-ft)

    Timing Chain Tensioner Bolt25 Nm (18 lb-ft)
11. 11

    Install camshafts and timing components
    Lubricate all camshaft journals and lobes with clean engine oil. Install camshafts in their original positions (intake and exhaust are different - verify markings). Install camshaft bearing caps in correct positions (marked during removal) with arrows pointing toward front of engine. Tighten bearing cap bolts in sequence from center outward in three passes: 1st pass - finger tight, 2nd pass - 7 Nm, 3rd pass - 14 Nm final torque. Verify camshafts rotate smoothly by hand. Align camshaft sprockets with timing chain using reference marks made during disassembly. Hold camshaft with wrench on hex and install sprocket bolts to specification. Verify all timing marks align correctly before proceeding.
    ⚠Camshaft bearing caps must go back in exact original positions. Mixing positions will cause binding and engine damage.
    Torque spec

    Camshaft Bearing Cap Bolts14 Nm (10 lb-ft)

    Camshaft Sprocket Bolt80 Nm (59 lb-ft)
12. 12

    Install timing cover and verify timing
    Install new timing cover gasket and O-ring seals. Apply small bead of RTV silicone to corners where cover meets block at oil pan junction. Position timing cover carefully over crankshaft nose and align all bolt holes. Install and hand-tighten all 8mm timing cover bolts, then torque in sequence to 25 Nm starting from center and working outward. Install crankshaft pulley and torque bolt to specification. Before releasing timing chain tensioner pin, rotate engine by hand two complete revolutions and verify all timing marks realign perfectly at TDC. If timing marks do not align, remove cover and repeat camshaft timing procedure. Once timing is verified, remove tensioner pin to release chain tension.
    ⚠️Do not start engine until timing has been verified by rotating crankshaft two full revolutions and confirming timing marks align.
    Torque spec

    Cover Bolts16 Nm (12 lb-ft)
13. 13

    Install manifolds and thermostat housing
    Install new thermostat housing gasket and position thermostat with jiggle valve at highest point. Install thermostat housing and torque bolts evenly. Position new exhaust manifold gasket and install exhaust manifold. Apply anti-seize compound to exhaust manifold stud threads. Install exhaust manifold nuts and torque in sequence from cold side to hot side (away from center outward) to 30 Nm. Install exhaust manifold heat shield. Install new intake manifold gasket - verify gasket tabs engage locating slots. Position intake manifold and install bolts finger-tight. Torque intake manifold bolts in sequence from center outward to 25 Nm.
    Torque spec

    Thermostat Housing Bolts15 Nm (11 lb-ft)

    Exhaust Manifold Nuts30 Nm (22 lb-ft)

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

    Install valve cover and reconnect components
    Install new valve cover gasket in cover groove - gasket should snap into place around entire perimeter. Apply small dab of RTV silicone at front corners where timing cover meets cylinder head. Position valve cover on head and install bolts finger-tight. Torque valve cover bolts in sequence from center outward to 10 Nm. Reconnect PCV hose and breather hose. Install ignition coils and torque bolts. Reconnect all ignition coil connectors. Reconnect fuel supply line, throttle body connector, and all injector connectors. Reconnect all coolant hoses, vacuum lines, and sensors using photos taken during disassembly.
    Torque spec

    Cover Bolts16 Nm (12 lb-ft)
15. 15

    Fill fluids and perform initial startup
    Fill engine with correct amount and specification of engine oil (5.0 quarts Hyundai Genuine 0W-20). Close radiator petcock and fill cooling system with Hyundai/Kia Long Life Coolant mixed to proper concentration (10 quarts total capacity). Leave radiator cap off. Reconnect negative battery cable. Turn ignition to ON position without starting engine and verify no warning lights indicate problems. Start engine and immediately verify oil pressure indicator goes off. Allow engine to idle and monitor for any unusual noises, vibrations, or leaks. Watch coolant level and add as needed while air bleeds from system. Once engine reaches operating temperature, check for leaks at all gasket surfaces. Rev engine gradually to 2500 RPM several times to verify smooth operation.
    ⚠Monitor oil pressure immediately on startup. If oil pressure light stays on, shut down engine immediately and investigate.
    ⚠Stay clear of moving belts and hot exhaust components during initial startup and warm-up.

Reassembly

1. Reinstall front engine mount after verifying engine runs properly
2. Install air filter housing and intake duct
3. Install engine cover and plastic under-tray panels
4. Perform complete cooling system air purge procedure per manufacturer specifications
5. Top off all fluids to proper levels after engine has cooled completely
6. Reset maintenance reminder if equipped

Verification

• Verify engine starts readily and idles smoothly with no misfires or unusual noises
• Check for any coolant, oil, or exhaust leaks around all gasket surfaces after engine reaches operating temperature
• Verify proper oil pressure at idle and under acceleration
• Test drive vehicle and confirm normal power delivery with no hesitation or performance issues
• Scan for any diagnostic trouble codes using OBD-II scanner - no codes should be present
• Re-check all fluid levels after test drive and top off as necessary
• After 50-100 miles, re-torque valve cover bolts and check for any developing leaks

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