Complete replacement of all hydraulic valve lifters/tappets on the 2.5L Smartstream I4 engine, requiring removal of camshafts and timing components.

Warnings

Tools required

Parts

• Hydraulic valve lifters/tappets (16 pieces) × 16 — Use OEM Hyundai/Kia specification
• Valve cover gasket × 1 — Use OEM specification
• Valve cover spark plug tube seals × 4 — Use OEM specification
• Timing chain cover gasket × 1 — Use OEM specification
• Camshaft position sensor O-rings × 2 — Use OEM specification
• Engine oil and filter × 1 — 0W-20 synthetic
• RTV silicone sealant (timing cover) × 1 — Hyundai approved anaerobic sealant

Fluids

• Hyundai Genuine 0W-20 engine oil — 5 qt

Preparation

1. Ensure engine is completely cold (8+ hours after last operation)
2. Disconnect negative battery cable and wait 3 minutes for airbag system discharge
3. Remove engine cover by pulling upward on front clips
4. Drain engine oil completely and remove oil filter
5. Remove air intake assembly from air filter box to throttle body
6. Disconnect all electrical connectors from valve cover (ignition coils, cam sensors)
7. Remove ignition coils (4 bolts) and spark plugs to prevent cross-threading during reassembly
8. Support engine from below using jack and wood block under oil pan, or install engine support fixture from above
9. Label and photograph all wiring harness routing for reassembly reference
10. Prepare clean workspace with magnetic trays labeled for each cylinder's components

Procedure

1. 1

   Remove valve cover
   Remove PCV hoses and breather connections from valve cover. Remove valve cover bolts in reverse of tightening sequence (outside to inside). Carefully lift valve cover straight up to avoid damaging gasket mating surfaces. Inspect valve cover for cracks or warping.
   Torque spec

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

   Set engine to TDC cylinder #1
   Rotate crankshaft clockwise using 22mm socket on crankshaft pulley bolt until timing marks on camshaft sprockets align with marks on timing chain cover (both camshaft lobes for cylinder #1 pointing upward and outward). Verify TDC mark on crankshaft pulley aligns with timing cover pointer. Lock crankshaft in position if tool is available.
   ⚠Only rotate engine clockwise (viewed from front). Counter-clockwise rotation can damage timing chain tensioner.
3. 3

   Remove timing chain cover (upper section)
   Remove upper timing chain cover bolts. Note that some bolts are different lengths - photograph or label positions. Carefully separate cover from cylinder head using plastic pry tools only. Do not pry against aluminum sealing surfaces. Clean all RTV residue from mating surfaces using plastic scraper.
   Torque spec

   Cover Bolts16 Nm (12 lb-ft)
4. 4

   Mark and secure timing chain position
   Mark timing chain position relative to both camshaft sprockets and crankshaft sprocket using paint pen or permanent marker. Install timing chain wedges or zip-tie chain to sprockets to prevent chain from jumping position. Photograph timing alignment for reference.
   ⚠️Timing chain MUST remain engaged with crankshaft sprocket throughout this procedure. If chain disengages, complete retiming procedure is required.
5. 5

   Mark and remove camshaft bearing caps
   Using paint pen, mark each camshaft bearing cap with its position number and orientation arrow pointing toward intake side. Caps are numbered from timing chain end. Loosen camshaft bearing cap bolts in reverse sequence (outside to inside) in 2-3 passes, turning each bolt 1/4 turn per pass to prevent warping. Remove caps and store in order.
   ⚠️Bearing caps are NOT interchangeable. Each cap must return to its exact original position or camshaft seizure will occur.
   ⚠Loosen bolts gradually and evenly. Sudden release can warp camshaft or crack bearing caps due to valve spring pressure.
   Torque spec

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

   Remove camshafts
   Carefully lift intake camshaft straight up, keeping timing chain secured to sprocket. Remove sprocket bolt and separate chain from sprocket while keeping chain supported. Repeat for exhaust camshaft. Support timing chain with wire to prevent falling into engine. Inspect camshaft lobes and bearing journals for wear, scoring, or discoloration.
   ⚠Do not allow timing chain to fall into timing cover. Chain must remain engaged with crankshaft sprocket.
7. 7

   Remove rocker arms or cam followers
   If equipped with rocker arms, remove rocker arm shaft bolts evenly and lift assembly. If direct-acting (no rocker arms), this step may not apply - proceed to lifter removal. Keep all rocker arms in cylinder order using numbered containers or magnetic tray sections.
   Torque spec

   Rocker Arm Shaft Bolts25 Nm (18 lb-ft)
8. 8

   Remove and inspect lifters
   Using magnetic pickup tool or fingers, carefully remove all 16 hydraulic lifters from their bores. Place each lifter in labeled container matching cylinder number and intake/exhaust position. Inspect lifter bores for scoring, debris, or damage. Inspect lifter contact surfaces - any pitting, scoring, or uneven wear indicates additional valve train damage requiring further inspection.
   ⚠Lifters MUST be kept in original order if reusing any. Mixed lifters will have incorrect wear patterns.
9. 9

   Clean and prepare cylinder head
   Thoroughly clean all lifter bores using clean lint-free shop towels and brake cleaner. Remove any sludge, varnish, or debris. Inspect cam bearing surfaces in cylinder head for scoring or excessive wear. Clean all oil passages with compressed air (wear eye protection). Verify all surfaces are completely clean and dry before proceeding.
10. 10

    Prime and install new lifters
    Submerge each new lifter in fresh 0W-20 engine oil and pump plunger 10-15 times to prime internal check valve. Coat lifter body liberally with fresh engine oil. Install each lifter into its corresponding bore, rotating slightly while inserting to ensure proper seating. Verify lifter moves freely in bore without binding.
    ⚠Installing dry lifters will cause severe engine noise and potential camshaft damage on first startup. All lifters must be fully primed with oil.
11. 11

    Reinstall rocker arms (if equipped)
    If rocker arms were removed, apply fresh engine oil to all rocker arm contact surfaces and shafts. Install rocker arm assembly ensuring proper orientation (oil holes facing down). Tighten rocker arm shaft bolts evenly in sequence from center outward in 3 passes to final torque.
    Torque spec

    Rocker Arm Shaft Bolts25 Nm (18 lb-ft)
12. 12

    Reinstall camshafts and bearing caps
    Apply fresh engine oil to all camshaft bearing journals and lobes. Position timing chain on intake camshaft sprocket aligned with original marks. Carefully lower intake camshaft into position. Repeat for exhaust camshaft. Install bearing caps in exact original positions with orientation marks correct. Hand-start all bearing cap bolts. Tighten in sequence from center outward in 3 passes: first pass 7 Nm, second pass 10 Nm, final pass 14 Nm.
    ⚠️Verify timing marks align perfectly before tightening bearing caps. Incorrect timing will destroy engine when started.
    ⚠Tighten in proper sequence. Out-of-sequence tightening will warp camshafts causing premature wear or seizure.
    Torque spec

    Camshaft Bearing Cap Bolts14 Nm (10 lb-ft)
13. 13

    Verify valve timing and install timing cover
    Rotate crankshaft two complete revolutions clockwise and verify all timing marks realign at TDC. Timing marks should align exactly - any deviation requires disassembly and correction. Apply thin bead of Hyundai-approved anaerobic sealant to timing cover mating surface. Install timing cover and tighten bolts to specification in crisscross pattern.
    ⚠️If timing marks do not realign exactly after two crankshaft rotations, DO NOT proceed. Disassemble and correct timing.
    Torque spec

    Cover Bolts16 Nm (12 lb-ft)
14. 14

    Reinstall valve cover
    Install new valve cover gasket and spark plug tube seals. Ensure gasket is properly seated in valve cover groove. Position valve cover carefully onto cylinder head, ensuring no gasket displacement. Install valve cover bolts and tighten in sequence from center outward to 10 Nm (7 lb-ft). Install ignition coils and torque to specification. Install spark plugs and torque to 20-25 Nm (15-18 lb-ft).
    Torque spec

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

    Complete final assembly and fill fluids
    Reconnect all electrical connectors to ignition coils and camshaft position sensors. Install air intake assembly. Install new oil filter and fill engine with 5.0 quarts of Hyundai Genuine 0W-20 synthetic engine oil. Reconnect battery negative cable. Do not start engine yet.
    ⚠Ensure oil level is correct before attempting to start engine. Low oil level with new lifters can cause immediate damage.

Reassembly

1. Double-check all electrical connectors are fully seated with audible clicks
2. Verify all bolts are torqued to specification - create checklist to confirm each component
3. Verify no tools or rags remain in engine compartment
4. Check that timing chain cover has no oil seepage before starting engine

Verification

• Turn ignition to ON position (do not start) and verify no warning lights remain illuminated after bulb check
• Crank engine for 5-10 seconds without starting (disable fuel or ignition) to build oil pressure and prime lifters
• Start engine and immediately verify oil pressure warning light extinguishes within 2-3 seconds
• Listen for abnormal valve train noise - some ticking is normal for first 30-60 seconds as lifters fully prime
• Allow engine to idle for 5 minutes, monitoring for oil leaks around valve cover and timing chain cover
• Verify no check engine light illuminates and engine runs smoothly without misfires
• After cool-down, recheck oil level and top off if necessary (lifters will retain some oil)
• Test drive vehicle through full RPM range and verify normal operation
• Recheck valve cover and timing cover for leaks after first 50 miles of operation
• Change oil and filter again at 500 miles to remove any break-in debris

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