This procedure covers replacement of a single valve spring on a 2018-2024 Toyota Camry 2.5L I4 engine, requiring removal of the valve cover, camshafts, and use of a valve spring compressor.

Warnings

Tools required

Parts

• Valve spring (specify intake or exhaust) × 1 — Use OEM specification
• Valve cover gasket × 1 — Use OEM specification
• Valve cover spark plug tube seals × 4 — Use OEM specification
• Camshaft cap bolts (if needed) × 1 — Use OEM specification
• Engine oil × 1 — Toyota Genuine 0W-20

Fluids

• Toyota Genuine 0W-20 — 5 qt

Preparation

1. Ensure engine is completely cold to the touch
2. Disconnect negative battery terminal and wait 90 seconds for airbag system discharge
3. Remove engine cover by pulling upward on integrated clips
4. Remove ignition coils from all four cylinders by disconnecting electrical connectors and removing mounting bolts
5. Label and photograph all vacuum hoses and electrical connections on valve cover for reinstallation reference
6. Disconnect PCV hoses and any breather hoses from valve cover
7. Place clean shop towels around engine bay to catch any dropped components

Procedure

1. 1

   Remove spark plugs
   Remove all four spark plugs using a 16mm spark plug socket with extension. Keep plugs organized by cylinder number for inspection. This provides access to the combustion chambers and prevents damage during camshaft removal.
   Torque spec

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

   Remove valve cover
   Remove valve cover bolts in reverse of tightening sequence (outside to inside pattern). Carefully lift valve cover straight up to avoid damaging gasket surfaces. If stuck, gently tap with a rubber mallet - do not pry between mating surfaces.
   Torque spec

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

   Rotate engine to TDC cylinder 1
   Using a 19mm socket on the crankshaft bolt, rotate engine clockwise until cylinder 1 is at top dead center on compression stroke. Verify timing marks on camshaft gears align with cylinder head reference marks. Use paint or marker to mark exact position of both camshaft gears relative to cylinder head and timing chain.
   ⚠This is critical for maintaining valve timing. Take clear photos of all timing marks before proceeding.
4. 4

   Support timing chain
   Secure timing chain to camshaft gears using zip ties or wire to prevent chain from dropping into timing cover when camshafts are removed. Place support underneath chain between the gears to maintain tension.
   ⚠️If timing chain falls into timing cover, major disassembly will be required to retrieve and retime the engine.
5. 5

   Remove camshaft caps
   Loosen camshaft bearing cap bolts in reverse order (outside caps first, center caps last) in multiple passes to prevent warping. Remove only the camshaft(s) necessary to access the affected valve - intake camshaft for intake valves, exhaust camshaft for exhaust valves. Keep caps in order with their bolts.
   ⚠Camshaft caps are directional and position-specific. Mark each cap clearly before removal.
   Torque spec

   Rocker Arm Bolts30 Nm (22 lb-ft)
6. 6

   Remove camshaft
   Carefully lift the camshaft straight up, ensuring timing chain remains secured to gear. Support camshaft horizontally on clean surface with lobes facing up. Inspect cam lobes and journals for wear or damage while removed.
   ℹ️Do not allow camshaft to rest on lobes. This can cause flat spots on the cam surface.
7. 7

   Remove rocker arm
   Lift the rocker arm from the affected valve and set aside. Note the orientation and position of any shims or hydraulic lash adjusters underneath. Keep these components clean and organized for reinstallation in the same position.
8. 8

   Compress and remove valve spring
   Install valve spring compressor tool onto the affected valve spring assembly. Ensure tool is centered and seated properly. Slowly compress spring until valve keepers (collets) are unloaded. Use magnetic tool to carefully remove both valve keepers and place in secure container. Slowly release spring compressor tension and remove spring retainer and valve spring. Inspect spring for cracks, wear, or deformation.
   ⚠️Valve keepers can launch across the shop if spring tension is released suddenly. Work slowly and maintain control.
   ⚠Do not allow valve to drop into cylinder. Stuff clean rags around valve stem if necessary.
9. 9

   Inspect valve and cylinder head
   With spring removed, inspect valve stem for wear, scoring, or damage. Check valve stem seal condition. Inspect valve spring seat area on cylinder head for debris or damage. Clean area thoroughly with compressed air and lint-free cloth. Verify valve moves freely in guide without excessive play.
   ⚠Cover spark plug hole with clean rag to prevent any debris from entering combustion chamber.
10. 10

    Install new valve spring
    Place new valve spring over valve stem with closer-wound coils toward cylinder head (if applicable to spring design). Install spring retainer over spring. Use valve spring compressor to compress new spring sufficiently to install valve keepers. Carefully seat both keepers in valve stem groove using magnetic tool. Slowly release compressor while watching to ensure keepers remain seated. After full release, gently tap valve stem tip with plastic tool to verify keepers are locked in place.
    ⚠Verify keeper groove is clean and free of carbon before installing keepers. Contamination can prevent proper seating.
11. 11

    Reinstall rocker arm
    Place hydraulic lash adjuster and any shims back in original position. Install rocker arm over valve stem, ensuring it seats properly on lash adjuster. Verify rocker arm moves freely and contacts valve stem correctly.
12. 12

    Reinstall camshaft
    Apply clean engine oil to all camshaft journals and lobes. Carefully lower camshaft into position, ensuring timing chain gear alignment marks still match reference marks made earlier. Verify all rocker arms are properly positioned under cam lobes.
13. 13

    Install camshaft caps
    Place camshaft bearing caps in correct positions and orientation. Hand-start all bolts. Rotate engine slightly if necessary to ensure cam lobes are pointing away from rocker arms being tightened. Tighten cap bolts in sequence from center caps outward in multiple progressive passes to specified torque.
    ⚠Tightening caps unevenly or with cam lobes pressing on valves can bend valves or damage camshaft.
    Torque spec

    Rocker Arm Bolts30 Nm (22 lb-ft)
14. 14

    Verify valve timing
    Remove timing chain supports. Manually rotate engine two complete revolutions clockwise using crankshaft bolt. Verify all timing marks realign correctly at TDC cylinder 1. Check that all valves move smoothly through their full range without binding.
    ⚠️If timing marks do not realign, stop immediately. Do not start engine. Timing must be corrected before proceeding.
15. 15

    Reinstall valve cover
    Clean valve cover and cylinder head gasket surfaces thoroughly with plastic scraper and brake cleaner. Install new valve cover gasket and spark plug tube seals. Ensure PCV valve and baffles are clean and properly seated in valve cover. Place valve cover onto cylinder head, ensuring gasket remains properly positioned. Install valve cover bolts and tighten in sequence from center outward.
    Torque spec

    Cover Bolts16 Nm (12 lb-ft)
16. 16

    Reinstall spark plugs and ignition coils
    Apply small amount of anti-seize compound to spark plug threads. Install spark plugs hand-tight, then torque to specification. Reinstall ignition coils and connect electrical connectors. Reconnect all vacuum hoses and breather hoses to valve cover.
    Torque spec

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

Reassembly

1. Reconnect negative battery terminal
2. Reinstall engine cover
3. Check engine oil level and top off if necessary with Toyota Genuine 0W-20
4. Consider performing oil change if contamination is suspected from repair work

Verification

• Start engine and verify it runs smoothly without unusual noises, ticking, or misfires
• Listen carefully for any valve train noise that would indicate improper assembly or timing
• Check for oil leaks around valve cover gasket after engine reaches operating temperature
• Allow engine to idle for 5 minutes, then rev slowly to 3000 RPM several times to verify smooth operation
• Scan for diagnostic trouble codes related to camshaft position or ignition misfires
• Test drive vehicle to confirm normal operation under load

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