This procedure covers removal and replacement of valve stem seals on the 2016-2024 Hyundai Tucson 2.5L I4 engine, requiring camshaft removal and valve spring compression.

Warnings

Tools required

Parts

• Valve stem seals (intake) × 8 — Use OEM specification
• Valve stem seals (exhaust) × 8 — Use OEM specification
• Valve cover gasket × 1 — Use OEM specification
• Valve cover bolt grommets × 12 — Use OEM specification
• Camshaft oil seal (front) × 1 — Use OEM specification
• Timing chain cover gasket × 1 — Use OEM specification
• Engine oil × 1 — Hyundai Genuine 0W-20
• Engine coolant × 1 — Hyundai/Kia Long Life Green
• Spark plugs × 4 — Use OEM specification

Fluids

• Hyundai Genuine 0W-20 — 5 qt
• Hyundai/Kia Long Life Coolant (Green) — 2 qt

Preparation

1. Ensure engine is completely cold (minimum 4 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 perimeter clips
4. Drain engine coolant into appropriate container by opening radiator drain and lower radiator hose
5. Drain engine oil completely and reinstall drain plug with new washer
6. Remove air intake duct and air filter housing assembly
7. Disconnect all electrical connectors from valve cover area (ignition coils, VVT solenoids, sensors)
8. Label and photograph all vacuum hoses and PCV connections before removal
9. Remove ignition coils (4 bolts) and set aside safely

Procedure

1. 1

   Remove valve cover and accessories
   Remove valve cover bolts in reverse of tightening sequence (outside to center pattern). Carefully lift valve cover away, tapping gently with plastic hammer if stuck. Remove any remaining hoses or brackets attached to valve cover. Inspect valve cover for warping or damage.
   Torque spec

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

   Set engine to TDC cylinder #1
   Rotate crankshaft clockwise using 19mm socket on crankshaft bolt until timing marks on camshaft gears align with marks on timing chain cover (both camshaft gears should have marks at 12 o'clock position). Verify cylinder #1 is on compression stroke by checking that both intake and exhaust valves are closed (rockers loose). Mark timing chain to camshaft gears with paint marker.
3. 3

   Remove timing chain components
   Remove timing chain upper guide bolts. Remove camshaft position sensors. Remove VVT solenoid valves from front of cylinder head. Support timing chain with wire to prevent it from falling into timing cover. Do not rotate crankshaft once chain is disconnected from camshaft gears.
   ⚠Support timing chain with mechanic wire to prevent it from dropping into oil pan. Chain must not slip off crankshaft sprocket.
   Torque spec

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

   Remove camshaft bearing caps and camshafts
   Label each camshaft bearing cap with permanent marker showing position and orientation (intake/exhaust, cylinder number, arrow pointing forward). Loosen camshaft bearing cap bolts in reverse sequence (outside bolts first, working toward center) in multiple passes (1/4 turn each pass) to gradually release valve spring tension. Remove bearing caps and store in order. Carefully lift intake and exhaust camshafts straight up and set aside on clean surface. Note camshaft position for reassembly.
   ⚠Camshaft caps MUST be reinstalled in exact original positions. Label clearly during removal or engine damage will occur.
   Torque spec

   Camshaft Cap Bolts14 Nm (10 lb-ft)
5. 5

   Remove rocker arms and lash adjusters
   Remove rocker arms from cylinder head, keeping them in order by cylinder and position (intake/exhaust). Use numbered plastic bags or parts organizer. Remove hydraulic lash adjusters from cylinder head bores and store upright in clean oil to prevent air entry. Keep all components organized by cylinder number for reassembly in original positions.
6. 6

   Install air pressure adapter and prepare cylinder #1
   Remove spark plug from cylinder #1. Install compressed air adapter (or use compressed air hose with rubber cone adapter) into spark plug hole. Apply 90-100 PSI compressed air to hold valves seated during seal replacement. Verify air pressure is maintaining (listen for leaks at exhaust or throttle body indicating rings or valve seat issues). This air pressure prevents valves from dropping into cylinder during spring compression.
   ⚠️Maintain constant air pressure while valve springs are compressed. Loss of pressure will allow valves to drop into cylinder.
   ⚠Engine may rotate slightly when air pressure is applied if not exactly at TDC. Block crankshaft from rotation.
   Torque spec

   Spark Plugs - Aluminum Head20 Nm (15 lb-ft)
7. 7

   Remove valve springs and seals for cylinder #1
   Install overhead cam valve spring compressor tool on intake valve of cylinder #1. Compress valve spring carefully until keepers are accessible. Use magnetic tool to remove both valve keepers (two half-moon pieces). Slowly release spring compressor and remove tool. Remove valve spring retainer, valve spring, and valve spring seat. Using pliers or seal removal tool, carefully extract old valve stem seal from valve guide. Repeat process for exhaust valve of cylinder #1. Keep intake and exhaust components separated.
   ⚠Valve keepers are easily dropped. Use magnetic retrieval tool and work slowly. Lost keeper requires cylinder head removal.
8. 8

   Install new valve seals for cylinder #1
   Lightly oil new valve stem seal with clean engine oil. Place seal on valve seal installation tool (correct size for 8mm valve stems). Carefully slide seal over valve stem and down to valve guide. Use plastic hammer to gently tap seal installation tool until seal seats fully on valve guide (seal will bottom out with distinct feel). Verify seal is fully seated and square on guide. Install valve spring seat, valve spring (tighter coils toward cylinder head), and spring retainer. Compress spring with tool and install both valve keepers in valve stem groove, ensuring they seat properly in retainer. Slowly release compressor while watching keepers remain seated. Tap valve stem tip lightly with plastic hammer to verify keepers are locked. Repeat for exhaust valve of cylinder #1.
9. 9

   Complete remaining cylinders #2, #3, and #4
   Remove air pressure adapter from cylinder #1 and reinstall spark plug finger-tight. Move to cylinder #2 and repeat steps 6-8 (remove spark plug, apply air pressure, replace valve seals). Continue sequence for cylinders #3 and #4. Maintain air pressure on each cylinder while working on its valves. Work methodically to avoid mixing components between cylinders. Verify each pair of valve keepers is fully seated before proceeding to next valve.
   ℹ️Work on one cylinder at a time, completing both intake and exhaust valves before moving to next cylinder.
10. 10

    Reinstall lash adjusters and rocker arms
    Install hydraulic lash adjusters into their original cylinder head bores. Ensure adjusters are primed with oil and install them upright to prevent air entry. Install rocker arms onto lash adjusters in their original positions (intake/exhaust per cylinder). Verify each rocker arm moves freely on its lash adjuster and valve stem tip.
11. 11

    Reinstall camshafts and bearing caps
    Apply clean engine oil to all camshaft journals and lobes. Install intake camshaft into front bearing saddles with timing mark positioned as noted during removal. Install exhaust camshaft similarly. Apply light coat of engine oil to bearing cap contact surfaces. Install bearing caps in exact original positions following labels (verify orientation with arrows pointing forward). Install camshaft cap bolts and tighten in sequence from center outward in multiple passes (first pass 5 Nm, second pass 10 Nm, final pass 14 Nm). Rotate camshafts by hand to verify smooth operation and proper valve clearance.
    ⚠Bearing caps in wrong positions will cause immediate engine failure. Verify each cap position against labels before final torque.
    Torque spec

    Camshaft Cap Bolts14 Nm (10 lb-ft)
12. 12

    Install timing chain and verify timing
    Verify crankshaft is still at TDC for cylinder #1. Align timing marks on camshaft gears with marks made during disassembly. Remove support wire from timing chain and install chain onto camshaft gears, ensuring paint marks align. Install timing chain guide and tighten bolts. Rotate engine two complete revolutions by hand and verify timing marks realign at TDC. Install VVT solenoids and camshaft position sensors with new O-rings if needed.
    ⚠️Incorrect valve timing will cause piston-to-valve contact and catastrophic engine damage. Verify timing marks align after two full crankshaft rotations before proceeding.
    Torque spec

    Sensor Bolts11 Nm (8 lb-ft)
13. 13

    Install spark plugs and valve cover
    Apply small amount of anti-seize compound to spark plug threads (avoid electrode area). Install all four spark plugs and torque to specification. Clean valve cover mating surface and cylinder head surface thoroughly with plastic scraper and clean towel (no gasket material or oil residue). Install new valve cover gasket and new bolt grommets. Position valve cover carefully and install bolts hand-tight. Torque valve cover bolts in sequence from center outward to specification.
    Torque spec

    Spark Plugs - Aluminum Head20 Nm (15 lb-ft)

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

    Reinstall accessories and refill fluids
    Reconnect all electrical connectors (ignition coils, VVT solenoids, sensors) and verify proper seating. Reinstall ignition coils. Reconnect PCV system and vacuum hoses per photos taken during disassembly. Reinstall air intake system. Fill engine with 5 quarts Hyundai Genuine 0W-20 engine oil. Refill cooling system with Hyundai/Kia Long Life Green coolant and bleed air from system. Reconnect battery negative cable.

Reassembly

1. Install engine cover by aligning clips and pressing firmly until all clips engage
2. Double-check all electrical connectors are fully seated and locked
3. Verify no tools or parts are left in engine compartment
4. Check engine oil level on dipstick and adjust if needed to full mark

Verification

• Start engine and verify no unusual valve train noise (ticking or tapping). Allow hydraulic lash adjusters to pump up (30-60 seconds of running)
• Check for oil leaks around valve cover gasket, camshaft seals, and timing cover while engine is running
• Rev engine gently to 3000 RPM and verify smooth operation with no misfires or abnormal sounds
• Check exhaust for blue smoke during warm-up and after reaching operating temperature. Smoke should be significantly reduced compared to before repair
• Monitor oil consumption over next 500 miles to verify valve seal replacement success
• Check coolant level after engine cools and top off if needed
• Verify no check engine light or diagnostic codes related to camshaft position or VVT operation

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