Replace a single faulty valve spring on a 2016-2024 Hyundai Tucson 2.5L I4 engine by removing the valve cover, rotating the engine to compress the affected valve, and swapping the spring without removing the cylinder head.

Warnings

Tools required

Parts

• Valve spring (single) × 1 — Use OEM Hyundai specification
• Valve spring retainer/keeper set × 1 — Use OEM specification
• Valve cover gasket × 1 — Use OEM specification
• Spark plug tube seals (set of 4) × 1 — Use OEM specification
• PCV valve grommet × 1 — Use OEM specification if damaged

Fluids

• Hyundai Genuine 0W-20 Engine Oil — 0.5 qt

Preparation

1. Ensure engine is completely cold before beginning work
2. Disconnect negative battery terminal and wait 3 minutes for airbag system to discharge
3. Remove engine cover by pulling upward on clips
4. Identify which cylinder has the faulty valve spring and note valve position (intake or exhaust)
5. Label and disconnect all electrical connectors from valve cover (ignition coils, PCV valve, sensors)
6. Remove air intake duct and air filter housing for access to front of engine
7. Place drain pan under vehicle in case of incidental fluid spillage

Procedure

1. 1

   Remove ignition coils and spark plugs
   Remove the four ignition coil mounting bolts and carefully pull each coil from its spark plug tube. Mark or label coil positions for reinstallation. Using a spark plug socket with extension, remove all four spark plugs. Inspect plugs and note condition. Keep plugs organized by cylinder number.
   Torque spec

   Spark Plugs - Aluminum Head20 Nm (15 lb-ft)
2. 2

   Remove valve cover assembly
   Disconnect PCV hose and any breather hoses from valve cover. Remove valve cover bolts in reverse of tightening sequence (work from outside toward center). Carefully lift valve cover away from cylinder head, breaking gasket seal with gentle prying if needed. Inspect valve cover gasket and spark plug tube seals - replace if worn or damaged.
   ⚠Do not pry between sealing surfaces. Use plastic tools only on gasket mating surfaces to avoid damage.
   Torque spec

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

   Identify and access the affected valve
   Locate the cylinder and valve (intake or exhaust) with the faulty spring. Inspect the camshaft lobes, rocker arms, and valve train components around the affected valve. Check for any obvious damage to rocker arms or cam lobes that may have caused the spring failure. Take photos for reference during reassembly.
4. 4

   Rotate engine to position affected valve
   Using a 22mm socket on the crankshaft pulley bolt, rotate the engine clockwise (viewed from front) until the affected valve is fully closed with the camshaft lobe pointing away from the valve (base circle position). Verify the valve is completely closed by visual inspection. This is critical to prevent valve drop.
   ⚠️The valve MUST be fully closed before proceeding. If uncertain, rotate engine to bring the piston of the affected cylinder to Top Dead Center on compression stroke (both valves closed).
5. 5

   Secure valve position with compressed air
   Thread a compressed air adapter into the spark plug hole of the affected cylinder. Apply regulated shop air at 90-100 psi to hold the valve against its seat. Maintain air pressure throughout the spring removal and installation process. As an alternative, the piston can be positioned at TDC compression stroke, though air pressure is the preferred method.
   ⚠Do not exceed 100 psi air pressure. The engine may rotate slightly when air is applied - this is normal as the piston seeks TDC.
   ℹ️If using rope/piston stop method instead of air, carefully feed soft nylon rope into cylinder through spark plug hole with piston at bottom, then rotate engine to compress rope against valve.
6. 6

   Remove rocker arm if necessary
   If the valve spring compressor cannot access the spring with the rocker arm in place, remove the rocker arm mounting bolt for the affected valve. Mark the rocker arm position and orientation. Carefully lift the rocker arm away and set aside in a clean area. Note the condition of the rocker arm roller and valve stem contact surface.
   ⚠Keep rocker arms organized and in order. They must be reinstalled in their original positions.
   Torque spec

   Rocker Arm Bolts30 Nm (22 lb-ft)
7. 7

   Compress and remove valve spring
   Position the valve spring compressor tool over the valve spring and retainer. Carefully compress the spring until the valve keepers (collets) are accessible. Using needle-nose pliers or a magnetic tool, carefully remove both valve keepers and place them in a secure container. Slowly release spring compressor pressure and remove the spring retainer, then the valve spring itself. Inspect the removed spring for breakage or damage.
   ⚠️Keep firm control of the valve spring compressor. Sudden release can cause injury or launch small parts into the engine.
   ⚠Valve keepers are tiny and easily lost. Use a magnetic parts tray and work carefully.
8. 8

   Inspect valve stem and guide
   With the spring removed and air pressure still applied, carefully inspect the exposed valve stem for wear, scoring, or damage. Check the valve guide condition by gently attempting to move the valve side-to-side (minimal movement is acceptable). Inspect the valve stem seal if visible - replace if torn or hardened. Clean any carbon deposits from the valve stem and spring seat area.
9. 9

   Install new valve spring
   Place the new valve spring onto the valve stem, ensuring it seats properly on the cylinder head spring seat. Verify spring orientation (closer-wound coils typically face down toward head). Position the valve spring retainer over the spring. Using the valve spring compressor, carefully compress the new spring until the keeper grooves on the valve stem are fully exposed.
   ⚠Ensure air pressure is still maintaining valve position. Check that valve has not moved during spring installation.
10. 10

    Install valve keepers and release spring
    Using needle-nose pliers or a magnetic tool, carefully install both valve keepers into the grooves on the valve stem under the compressed spring retainer. Ensure keepers are fully seated in their grooves and properly positioned around the entire circumference. Very slowly release the spring compressor while watching the keepers - they should lock into the retainer securely. Once fully released, tap the valve stem tip gently with a plastic tool to ensure keepers are fully seated.
    ⚠️If keepers are not properly seated, the spring will launch them when released. Release compressor very slowly and watch keeper engagement carefully.
11. 11

    Reinstall rocker arm if removed
    If the rocker arm was removed, ensure the camshaft lobe is still pointing away from the valve (base circle). Position the rocker arm in its original location with proper orientation. Install the rocker arm bolt and tighten to specification using a torque wrench. Verify the rocker arm moves freely and contacts the valve stem properly.
    ℹ️Rocker arm bolt must be tightened with cam lobe pointing away from valve as specified.
    Torque spec

    Rocker Arm Bolts30 Nm (22 lb-ft)
12. 12

    Remove air pressure and verify installation
    Remove the compressed air adapter from the spark plug hole. Manually rotate the engine at least two complete revolutions using the crankshaft pulley bolt. Watch the affected valve and rocker arm through the full rotation to ensure proper operation with no binding or unusual movement. Verify the valve spring keepers remain fully seated during rotation.
    ⚠Rotate engine slowly by hand. Listen and watch for any unusual sounds or movements that could indicate improper assembly.
13. 13

    Clean and prepare valve cover mating surface
    Thoroughly clean the valve cover mating surface on the cylinder head using a plastic scraper. Remove all old gasket material and oil residue. Clean the valve cover sealing surface as well. Wipe both surfaces with a lint-free cloth and brake cleaner. Ensure no debris or gasket pieces fall into the engine. Install new valve cover gasket and spark plug tube seals onto the valve cover.
14. 14

    Install valve cover
    Position the valve cover with new gasket carefully onto the cylinder head, ensuring proper alignment and that gasket remains in position. Install all valve cover bolts finger-tight first. Using a torque wrench, tighten valve cover bolts to specification in the proper sequence (start from center and work outward in a spiral pattern). Reconnect PCV hose and breather hoses.
    ⚠Over-tightening valve cover bolts can warp the cover or damage the gasket, causing oil leaks. Follow torque specification exactly.
    Torque spec

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

    Reinstall spark plugs and ignition coils
    Apply a small amount of anti-seize compound to the spark plug threads. Install all four spark plugs finger-tight, then torque to specification using a torque wrench. Install ignition coils into their original positions, ensuring they seat fully into the spark plug tubes. Install coil mounting bolts and tighten to specification. Reconnect all electrical connectors.
    ⚠Spark plugs in aluminum heads are easily cross-threaded. Start by hand and ensure threads engage smoothly before using tools.
    Torque spec

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

Reassembly

1. Reinstall air intake duct and air filter housing, ensuring all clamps are tight
2. Reconnect negative battery terminal
3. Install engine cover by pressing firmly until clips engage
4. Check engine oil level and top off if necessary - some oil may have been lost during valve cover removal

Verification

• Start engine and allow to idle - listen for any unusual valve train noise or ticking from the repaired cylinder
• Check for oil leaks around valve cover gasket, paying special attention to corners and spark plug tube seals
• Rev engine gently to 2500-3000 RPM and verify smooth operation with no misfires or abnormal sounds
• Allow engine to reach operating temperature and recheck for leaks
• Test drive vehicle under normal conditions and verify no check engine light, smooth acceleration, and normal engine performance
• After 50-100 miles, recheck valve cover bolt torque and inspect for any oil seepage

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