Complete timing chain replacement procedure for the 2018-2024 Toyota Camry 2.5L I4 engine, including removal of timing cover, chain, guides, tensioners, and related components.

Warnings

Tools required

Parts

• Timing chain kit (chain, guides, tensioner) × 1 — Use OEM specification
• Timing cover gasket × 1 — Use OEM specification
• Valve cover gasket × 1 — Use OEM specification
• Crankshaft front seal × 1 — Use OEM specification
• Oil pump O-ring × 1 — Use OEM specification
• RTV silicone sealant (Toyota Genuine or equivalent) × 1 — 08826-00080
• Engine oil and filter × 1 — Use OEM specification
• Oil drain plug crush washer × 1 — 90430-12031

Fluids

• Toyota Genuine 0W-20 — 5 qt
• Toyota Super Long Life Coolant (Pink) — 2 qt

Preparation

1. Ensure engine is completely cold before beginning work
2. Disconnect negative battery cable and wait 90 seconds for airbag system discharge
3. Remove engine under cover and splash shields
4. Drain engine oil and coolant into appropriate containers
5. Remove right front wheel and inner fender liner for access to crankshaft pulley
6. Install engine support fixture or support engine from above with hoist
7. Remove or loosen accessory drive belt
8. Photograph all timing marks and component positions before disassembly
9. Verify you have the correct timing chain kit for the A25A-FKS engine (not A25A-FXS hybrid variant)

Procedure

1. 1

   Remove Upper Engine Components
   Remove engine cover, air intake assembly, and ignition coils. Disconnect PCV hoses and any harness connectors attached to valve cover. Remove valve cover bolts in reverse of tightening sequence and carefully lift valve cover away. Inspect valve cover gasket and replace if damaged.
2. 2

   Remove Right Engine Mount and Accessories
   Support engine weight with fixture. Remove right-side engine mount and bracket to provide access to timing cover area. Remove alternator and A/C compressor (set aside without disconnecting refrigerant lines). Remove power steering pump if obstructing access. Tag all electrical connectors.
3. 3

   Remove Crankshaft Pulley
   Remove crankshaft pulley center bolt using appropriate holding tool to prevent engine rotation. This bolt is very tight (180 Nm installed). Use breaker bar or impact wrench. Once bolt is removed, use puller if pulley does not slide off easily. DO NOT pry against timing cover.
   ⚠Verify if crankshaft bolt is torque-to-yield (TTY) specification - if so, must be replaced with new bolt during reassembly.
4. 4

   Remove Timing Cover
   Disconnect crankshaft position sensor and any other sensors mounted to timing cover. Remove water pump inlet pipe if attached to timing cover. Remove all timing cover bolts - note there are three different sizes (6mm, 8mm, and 10mm) in specific locations. Carefully separate timing cover from block - may need to tap gently with plastic mallet. Do not pry on gasket surfaces.
   Torque spec

   Timing Cover Bolts12 Nm (9 lb-ft)
5. 5

   Verify and Mark Timing Positions
   Rotate crankshaft to TDC cylinder #1 (compression stroke). Verify timing marks on crankshaft sprocket and camshaft sprockets align with marks on chain guides and cylinder head. Take multiple photos. Mark chain-to-sprocket relationship with paint pen on all three sprockets before removal.
   ⚠️This is the most critical step - incorrect timing will cause valve-to-piston contact and catastrophic engine damage.
6. 6

   Remove Timing Chain Tensioner and Guides
   Remove VVT solenoid valves from cylinder head. Compress timing chain tensioner by pushing plunger inward and insert pin or paper clip to lock it. Remove tensioner mounting bolt and remove tensioner. Remove timing chain guide bolts and remove upper chain guide, lower chain guide, and idler sprocket.
   Torque spec

   Timing Chain Tensioner25 Nm (18 lb-ft)

   Timing Chain Guide Bolts12 Nm (9 lb-ft)
7. 7

   Remove Camshaft Sprockets
   Hold each camshaft stationary using wrench on hex section of camshaft (between lobes). Remove camshaft sprocket bolts and cam phaser bolts. Note that intake and exhaust cam phasers are different and not interchangeable. Mark which belongs to intake and exhaust. Remove sprockets and cam phasers as assemblies.
   ⚠Do not allow camshafts to rotate independently once chain is removed - can bend valves if pistons are not at safe position.
   Torque spec

   Camshaft Sprocket Bolts80 Nm (59 lb-ft)
8. 8

   Remove Timing Chain and Crankshaft Sprocket
   Lift timing chain off crankshaft sprocket. Remove crankshaft timing sprocket from crankshaft (may need gentle prying with screwdrivers on both sides evenly). Inspect sprocket teeth for wear, damage, or scoring. Remove oil pump chain and sprocket if replacement is needed.
9. 9

   Clean and Inspect Components
   Thoroughly clean all RTV sealant from timing cover and engine block mating surfaces using gasket scraper and solvent. Inspect chain guides for excessive wear (grooves deeper than 1mm require replacement). Clean oil passages in cylinder head and block. Inspect camshaft and crankshaft sprocket mounting surfaces for damage. Replace crankshaft front seal in timing cover.
   ℹ️Any residual RTV on sealing surfaces will cause oil leaks - surfaces must be completely clean and dry.
10. 10

    Install New Crankshaft Sprocket and Chain Guides
    Install crankshaft timing sprocket onto crankshaft with timing mark facing outward. Install lower timing chain guide and idler sprocket. Apply medium-strength threadlocker to guide bolts and torque to specification. Install upper chain guide.
    Torque spec

    Timing Chain Guide Bolts12 Nm (9 lb-ft)
11. 11

    Install New Timing Chain
    Verify crankshaft is still at TDC mark. Drape new timing chain over crankshaft sprocket, aligning colored link (or marked link) with timing mark on sprocket. Route chain around idler sprocket and up both sides to camshaft positions. Verify chain routing matches original configuration.
12. 12

    Install Camshaft Sprockets and Cam Phasers
    Position camshaft sprockets with cam phasers onto camshafts, aligning timing marks on sprockets with colored chain links. Ensure intake cam phaser goes on intake cam (front) and exhaust on exhaust cam (rear). Apply threadlocker to cam phaser bolts. Hold camshafts stationary with wrench on hex section and torque cam phaser bolts and sprocket bolts to specification in proper sequence.
    ⚠Verify timing marks are perfectly aligned before final torquing - even one tooth off will cause severe driveability issues or no-start condition.
    Torque spec

    Camshaft Sprocket Bolts80 Nm (59 lb-ft)
13. 13

    Install Timing Chain Tensioner
    Compress new timing chain tensioner plunger fully and insert retaining pin to lock it. Install tensioner to engine and torque mounting bolt to specification. Carefully remove retaining pin to allow tensioner to apply pressure to chain. Verify tensioner plunger extends and applies tension - you should see chain tighten.
    ⚠Do not remove tensioner pin until tensioner is fully bolted in place.
    Torque spec

    Timing Chain Tensioner25 Nm (18 lb-ft)
14. 14

    Verify Timing and Rotate Engine
    Double-check all timing marks are aligned. Rotate crankshaft by hand two complete revolutions clockwise (using 19mm socket on crankshaft bolt hole). Verify timing marks realign at TDC. Check that chain tension is even on both sides and chain does not bind. If marks do not realign perfectly, disassemble and correct timing before proceeding.
    ⚠️If you feel resistance when rotating engine, STOP immediately. Incorrect timing may cause piston-to-valve contact.
15. 15

    Install Timing Cover
    Install new timing cover gasket or apply RTV sealant per manufacturer specification (typically 2-3mm bead in gasket grooves). Apply sealant to corners where block meets oil pan. Install timing cover carefully, ensuring it seats fully against block. Install cover bolts in proper sequence - 6mm, 8mm, and 10mm bolts in correct locations. Torque in sequence per specification.
    ℹ️If using RTV sealant, engine must not be started for at least 2 hours to allow proper curing.
    Torque spec

    Timing Cover Bolts12 Nm (9 lb-ft)
16. 16

    Install Crankshaft Pulley
    Clean crankshaft nose and pulley bore. Install crankshaft pulley, aligning keyway. Install crankshaft pulley bolt (use new bolt if TTY specification). Hold crankshaft from rotating and torque bolt to 180 Nm specification. If TTY, follow additional angle rotation specification from service manual.
17. 17

    Reinstall Engine Components
    Reinstall VVT solenoid valves with new O-rings. Reinstall crankshaft position sensor. Install new valve cover gasket, position valve cover, and torque bolts in proper sequence. Reinstall ignition coils, PCV hoses, and all electrical connectors. Reinstall engine mount, alternator, A/C compressor, and power steering pump.

Reassembly

1. Reinstall accessory drive belt and verify proper tension and routing
2. Reinstall right front wheel inner fender liner and wheel, torque lug nuts to specification
3. Reinstall engine under covers and splash shields
4. Refill engine with 5 quarts Toyota Genuine 0W-20 oil and new filter
5. Refill coolant system with Toyota Super Long Life Coolant as needed
6. Reconnect negative battery cable
7. Do not start engine for minimum 2 hours if RTV sealant was used on timing cover

Verification

• Check for oil leaks around timing cover, valve cover, and crankshaft seal before starting engine
• Prime oil system by cranking engine with fuel pump fuse removed for 10-15 seconds
• Start engine and verify it starts normally without unusual noises
• Listen for timing chain noise or rattling - should be smooth and quiet
• Verify VVT system operates properly - no check engine light for cam correlation codes (P0011, P0021, etc.)
• Check for oil leaks after engine reaches operating temperature
• Monitor oil pressure gauge to ensure normal pressure
• Test drive vehicle and verify normal performance and no unusual engine noises
• Clear any stored diagnostic codes and verify no new codes set after test drive

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