Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001JJBE
Model Year Start: 2020 Model: Avalon HV Prod Date Range: [08/2019 -           ]
Title: A25A-FXS (ENGINE MECHANICAL): ENGINE UNIT: DISASSEMBLY; 2020 - 2022 MY Avalon HV [08/2019 -        ]

DISASSEMBLY

CAUTION / NOTICE / HINT

NOTICE:

This procedure includes the removal of small-head bolts. Refer to Small-Head Bolts of Basic Repair Hint to identify the small-head bolts.

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: PRECAUTION

PROCEDURE

1. REMOVE SPARK PLUG

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; MAINTENANCE: A25A-FXS SPARK PLUG: REMOVAL+

2. REMOVE KNOCK CONTROL SENSOR

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): KNOCK SENSOR: REMOVAL+

3. REMOVE ENGINE COOLANT TEMPERATURE SENSOR

Click here 2019 - 2021 MY Avalon HV [04/2018 - 08/2021]; A25A-FXS (ENGINE CONTROL): ENGINE COOLANT TEMPERATURE SENSOR: REMOVAL+ 2022 MY Avalon HV [08/2021 -        ]; A25A-FXS (ENGINE CONTROL): ENGINE COOLANT TEMPERATURE SENSOR: REMOVAL+

4. REMOVE STRAIGHT SCREW PLUG

(a) Remove the straight screw plug and gasket from the cylinder block sub-assembly.

5. REMOVE OIL PRESSURE AND TEMPERATURE SENSOR

Click here 2020 - 2022 MY Avalon HV [08/2019 -        ]; A25A-FXS (LUBRICATION): OIL PRESSURE AND TEMPERATURE SENSOR: REMOVAL+

6. REMOVE OIL PRESSURE CONTROL VALVE ASSEMBLY

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (LUBRICATION): OIL PRESSURE SWITCHING VALVE: REMOVAL+

7. REMOVE CAMSHAFT POSITION SENSOR (for Intake Side)

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): CAMSHAFT POSITION SENSOR: REMOVAL+

8. REMOVE CAMSHAFT POSITION SENSOR (for Exhaust Side)

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): CAMSHAFT POSITION SENSOR: REMOVAL+

9. REMOVE CAM TIMING OIL CONTROL SOLENOID ASSEMBLY

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): CAMSHAFT OIL CONTROL SOLENOID: REMOVAL+

10. REMOVE O-RING

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): CAMSHAFT OIL CONTROL SOLENOID: REMOVAL+

11. REMOVE CAM TIMING CONTROL MOTOR WITH EDU ASSEMBLY

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12. REMOVE CAM TIMING CONTROL MOTOR O-RING

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13. REMOVE WATER INLET WITH THERMOSTAT SUB-ASSEMBLY

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14. REMOVE ENGINE WATER PUMP ASSEMBLY (WATER INLET HOUSING)

(a) Remove the 4 bolts, engine water pump assembly (water inlet housing) and gasket from the cylinder block sub-assembly.

15. REMOVE OIL FILLER CAP SUB-ASSEMBLY

(a) Remove the oil filler cap sub-assembly from the cylinder head cover sub-assembly.

16. REMOVE OIL FILLER CAP GASKET

(a) Remove the oil filler cap gasket from the oil filler cap sub-assembly.

17. REMOVE CRANKSHAFT POSITION SENSOR

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): CRANKSHAFT POSITION SENSOR: REMOVAL+

18. REMOVE PCV VALVE (VENTILATION VALVE SUB-ASSEMBLY)

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (EMISSION CONTROL): PCV VALVE: REMOVAL+

19. REMOVE CRANKSHAFT PULLEY ASSEMBLY

(a) Using SST, hold the crankshaft pulley assembly and loosen the crankshaft pulley bolt. Further loosen the crankshaft pulley bolt until 2 or 3 threads remain screwed into the crankshaft.

*a

Hold

Turn

SST: 09213-54015

SST: 09330-00021

(b) Using SST and the crankshaft pulley bolt, remove the crankshaft pulley assembly and crankshaft pulley bolt.

*1

Crankshaft Pulley Bolt

*a

Hold

Turn

SST: 09950-50013

09951-05010

09952-05010

09953-05020

09954-05070

09957-04010

HINT:

Apply lubricant to the threads and end of SST.

20. REMOVE WATER OUTLET

(a) Using an 8 mm socket wrench, remove the 3 bolts, water outlet and water outlet gasket from the cylinder head sub-assembly.

21. REMOVE WATER BY-PASS OUTLET

(a) Using an 8 mm socket wrench, remove the 3 bolts, water by-pass outlet and outlet water pipe gasket from the cylinder head sub-assembly.

22. REMOVE CYLINDER HEAD COVER SUB-ASSEMBLY

(a) Using an 8 mm socket wrench, remove the 4 bolts (A).

(b) Remove the 12 bolts (B) and cylinder head cover sub-assembly from the camshaft housing sub-assembly.

(c) Remove the 7 cylinder head cover gaskets from the cylinder head cover sub-assembly.

(d) Remove the camshaft bearing cap oil hole gasket from the No. 1 camshaft bearing cap.

23. REMOVE SPARK PLUG TUBE GASKET

(a) Using a screwdriver, pry out the 4 spark plug tube gaskets from the cylinder head cover sub-assembly.

NOTICE:

Be careful not to damage the cylinder head cover sub-assembly.

HINT:

Tape the screwdriver tip before use.

*a

Protective Tape

24. REMOVE ENGINE MOUNTING BRACKET RH

(a) Remove the 3 bolts and engine mounting bracket RH from the No. 2 timing chain cover assembly.

25. REMOVE STRAIGHT SCREW PLUG

(a) Using a 10 mm hexagon wrench, remove the straight screw plug from the No. 2 timing chain cover assembly.

26. REMOVE NO. 2 TIMING CHAIN COVER ASSEMBLY

(a) Remove the 20 bolts.

(b) Remove the No. 2 timing chain cover assembly from the timing chain cover assembly by prying the No. 2 timing chain cover assembly with a screwdriver with its tip wrapped with protective tape.

*a

Protective Tape

-

-

NOTICE:

Be careful not to damage the contact surfaces of the No. 2 timing chain cover assembly and timing chain cover assembly.

27. REMOVE TIMING CHAIN COVER OIL SEAL

(a) Using a screwdriver and wooden block, pry out the timing chain cover oil seal.

NOTICE:

Do not damage the surface of the timing chain cover oil seal press fit hole.

HINT:

Tape the screwdriver tip before use.

*a

Protective Tape

*b

Wooden Block

28. SET NO. 1 CYLINDER TO TDC (COMPRESSION)

(a) Temporarily install the crankshaft pulley bolt.

*1

Crankshaft Timing Gear Key

-

-

*a

Approximately 7.4°

*b

Approximately 27.3°

*c

Approximately 24.3°

*d

Timing Mark

(b) Rotate the crankshaft clockwise and align the crankshaft timing gear key as shown in the illustration.

(c) Check that the timing marks on the camshaft timing exhaust gear assembly and camshaft timing gear assembly are as shown in the illustration.

(d) Remove the crankshaft pulley bolt.

HINT:

As the No. 2 camshaft may rotate counterclockwise strongly when the crankshaft pulley bolt is removed, use a wrench to hold the hexagonal portion of the No. 2 camshaft.

29. REMOVE OIL PUMP DRIVE CHAIN SUB-ASSEMBLY

(a) Temporarily install the crankshaft pulley assembly with the crankshaft pulley bolt.

(b) Using SST, hold the crankshaft pulley assembly and remove the bolt.

SST: 09213-54015

SST: 09330-00021

*a

Bolt

(c) Remove SST, the crankshaft pulley bolt and crankshaft pulley assembly.

(d) Remove the chain tensioner plate and chain damper spring.

*1

Chain Tensioner Plate

*2

Chain Damper Spring

(e) Remove the oil pump drive sprocket, oil pump drive shaft sprocket and oil pump drive chain sub-assembly.

*1

Oil Pump Drive Chain Sub-assembly

*2

Oil Pump Drive Sprocket

*3

Oil Pump Drive Shaft Sprocket

30. REMOVE CAMSHAFT TIMING GEAR ASSEMBLY

(a) Hold the hexagonal portion of the No. 2 camshaft with a wrench and turn the camshaft timing exhaust gear assembly clockwise to loosen the chain sub-assembly between the camshaft timing exhaust gear assembly and camshaft timing gear assembly.

*a

Loosen

Turn

(b) Using a wrench, hold the hexagonal portion of the camshaft.

NOTICE:

  • Be careful not to damage the camshaft housing sub-assembly, cylinder head sub-assembly and spark plug tube with the wrench.
  • Do not disassemble the camshaft timing gear assembly.

*a

Hold

Turn

(c) Using a 10 mm bi-hexagonal wrench, remove the bolt and camshaft timing gear assembly from the camshaft.

31. REMOVE CHAIN SUB-ASSEMBLY

(a) Remove the crankshaft timing sprocket and chain sub-assembly.

32. REMOVE NO. 1 CHAIN TENSIONER ASSEMBLY

(a) Using an 8 mm socket wrench, remove the bolt.

(b) Remove the nut and No. 1 chain tensioner assembly.

NOTICE:

Make sure that the plunger, check ball assembly and spring do not come out.

(c) Use tape to hold the plunger inside the No. 1 chain tensioner assembly.

*a

Tape

NOTICE:

  • Make sure that the plunger, check ball assembly and spring do not come out.
  • If the No. 1 chain tensioner assembly comes apart, reinstall the parts as shown in the illustration.

    *a

    Plunger

    *b

    Check ball assembly

    *c

    Spring

    *d

    No. 1 chain tensioner assembly body

33. REMOVE CHAIN TENSIONER SLIPPER

(a) Remove the bolt and chain tensioner slipper.

34. REMOVE NO. 1 CHAIN VIBRATION DAMPER

(a) Remove the 2 bolts and No. 1 chain vibration damper.

35. REMOVE CAMSHAFT TIMING EXHAUST GEAR ASSEMBLY

(a) Using a wrench, hold the hexagonal portion of the No. 2 camshaft.

NOTICE:

Be careful not to damage the camshaft housing sub-assembly, cylinder head sub-assembly and spark plug tube with the wrench.

(b) Using a 5 mm hexagon socket wrench, remove the 3 bolts.

(c) Remove the camshaft timing exhaust gear assembly and camshaft timing oil control valve assembly (exhaust camshaft timing gear bolt assembly).

*1

Camshaft Timing Exhaust Gear Assembly

*2

Camshaft Timing Oil Control Valve Assembly (Exhaust Camshaft Timing Gear Bolt Assembly)

36. REMOVE TIMING CHAIN COVER ASSEMBLY

(a) Remove the 19 bolts from the camshaft housing sub-assembly, cylinder head sub-assembly, cylinder block sub-assembly, stiffening crankcase assembly and oil pump assembly.

(b) Remove the timing chain cover assembly by prying between the cylinder head sub-assembly, camshaft housing sub-assembly, cylinder block sub-assembly, oil pump assembly and stiffening crankcase assembly with a screwdriver with its tip wrapped with protective tape.

*a

Protective Tape

-

-

NOTICE:

Be careful not to damage the contact surfaces of the cylinder head sub-assembly, camshaft housing sub-assembly, cylinder block sub-assembly, oil pump assembly, stiffening crankcase assembly and timing chain cover assembly.

37. REMOVE OIL NOZZLE VALVE SUB-ASSEMBLY

(a) Remove the oil nozzle valve sub-assembly from the cylinder block sub-assembly.

38. REMOVE CRANKSHAFT TIMING GEAR KEY

(a) Using a screwdriver, remove the 2 crankshaft timing gear keys.

NOTICE:

Be careful not to damage the crankshaft.

HINT:

Tape the screwdriver tip before use.

*a

Protective Tape

39. REMOVE FUEL PUMP LIFTER GUIDE

(a) Using an 8 mm socket wrench, remove the 2 bolts and fuel pump lifter guide from the No. 4 camshaft bearing cap.

40. REMOVE CAMSHAFT HOUSING SUB-ASSEMBLY

(a) Uniformly loosen and remove the 18 bolts in the order shown in the illustration.

(b) Remove the camshaft housing sub-assembly by prying between the cylinder head sub-assembly and camshaft housing sub-assembly with a screwdriver.

NOTICE:

Be careful not to damage the contact surfaces of the cylinder head sub-assembly and camshaft housing sub-assembly.

HINT:

Tape the screwdriver tip before use.

41. REMOVE CAMSHAFT BEARING CAP

(a) Remove the 8 bolts in the order shown in the illustration.

*1

No. 1 Camshaft Bearing Cap

*2

No. 2 Camshaft Bearing Cap

*3

No. 3 Camshaft Bearing Cap

*4

No. 4 Camshaft Bearing Cap

(b) Remove the No. 1 camshaft bearing cap, No. 2 camshaft bearing cap, 2 No. 3 camshaft bearing caps and No. 4 camshaft bearing cap.

HINT:

Arrange the removed parts in such a way that they can be reinstalled to their original locations.

42. REMOVE CAMSHAFT

(a) Remove the camshaft from the camshaft housing sub-assembly.

43. REMOVE NO. 2 CAMSHAFT

(a) Remove the No. 2 camshaft from the camshaft housing sub-assembly.

44. REMOVE NO. 1 VALVE ROCKER ARM SUB-ASSEMBLY

(a) Remove the 16 No. 1 valve rocker arm sub-assemblies.

HINT:

Arrange the removed parts in such a way that they can be reinstalled to their original locations.

45. REMOVE VALVE LASH ADJUSTER ASSEMBLY

(a) Remove the 16 valve lash adjuster assemblies from the cylinder head sub-assembly.

HINT:

Arrange the removed parts in such a way that they can be reinstalled to their original locations.

46. REMOVE VALVE STEM CAP

(a) Remove the 16 valve stem caps from the cylinder head sub-assembly.

HINT:

Arrange the removed parts in such a way that they can be reinstalled to their original locations.

47. REMOVE WATER SEAL PLATE (w/o No. 3 Straight Screw Plug)

(a) Using an 8 mm socket wrench, remove the 2 bolts, water seal plate and gasket from the cylinder head sub-assembly.

48. REMOVE NO. 3 STRAIGHT SCREW PLUG (w/ No. 3 Straight Screw Plug)

(a) Using a 14 mm straight hexagon wrench, remove the No. 3 straight screw plug from the cylinder head sub-assembly.

49. REMOVE CYLINDER HEAD SUB-ASSEMBLY

(a) Using a 12 mm socket wrench, uniformly loosen the 10 cylinder head set bolts in the order shown in the illustration. Remove the 10 cylinder head set bolts and 10 plate washers.

Front of Engine

NOTICE:

  • Be careful not to drop the plate washers into the cylinder head sub-assembly.
  • Warpage or cracking of the cylinder head sub-assembly may result from removing the cylinder head set bolts in the incorrect order.

HINT:

Arrange the removed parts in such a way that they can be reinstalled to their original locations.

(b) Remove the cylinder head sub-assembly from the cylinder block sub-assembly.

50. REMOVE CYLINDER HEAD GASKET

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51. REMOVE CYLINDER BLOCK WATER JACKET SPACER

(a) Remove the cylinder block water jacket spacer from the exhaust side of the cylinder block sub-assembly.

NOTICE:

Be sure to remove the cylinder block water jacket spacer. If it is not removed, it may fall and become damaged when the cylinder block sub-assembly is inverted.

52. REMOVE OIL FILTER SUB-ASSEMBLY

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53. REMOVE OIL PAN DRAIN PLUG

(a) Remove the oil pan drain plug and gasket from the No. 2 oil pan sub-assembly.

54. REMOVE OIL FILTER UNION

(a) Using a 12 mm hexagon socket wrench, remove the oil filter union from the stiffening crankcase assembly.

55. REMOVE NO. 2 OIL PAN SUB-ASSEMBLY

(a) Remove the 11 bolts and 2 nuts.

*a

Nut

(b) Insert the blade of an oil pan seal cutter between the No. 2 oil pan sub-assembly and stiffening crankcase assembly, cut through the applied sealer and remove the No. 2 oil pan sub-assembly.

NOTICE:

  • Be careful not to damage the contact surfaces of the stiffening crankcase assembly and No. 2 oil pan sub-assembly.
  • Be careful not to damage the No. 2 oil pan sub-assembly flange.

56. REMOVE OIL STRAINER SUB-ASSEMBLY

(a) Using an 8 mm socket wrench, remove the bolt, oil strainer sub-assembly and oil strainer gasket.

57. REMOVE ENGINE OIL LEVEL SENSOR

Click here 2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (LUBRICATION): OIL PAN AND OIL LEVEL SENSOR: REMOVAL+

58. REMOVE OIL PUMP BRACKET

(a) Remove the 2 bolts and oil pump bracket.

59. INSPECT CRANKSHAFT BACKLASH

(a) Using a dial indicator, measure the backlash of the crankshaft and balance shaft as shown in the illustration.

Standard Backlash:

0.05 to 0.20 mm (0.00197 to 0.00787 in.)

Maximum Backlash:

0.20 mm (0.00787 in.)

If the backlash is more than the maximum, replace the engine balancer assembly.

60. REMOVE ENGINE BALANCER ASSEMBLY

(a) Remove the 6 bolts and engine balancer assembly from the stiffening crankcase assembly.

NOTICE:

Do not disassemble the engine balancer assembly.

61. REMOVE OIL PUMP ASSEMBLY

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62. REMOVE STIFFENING CRANKCASE ASSEMBLY

(a) Remove the 7 bolts.

(b) Using a screwdriver, remove the stiffening crankcase assembly by prying between the stiffening crankcase assembly and cylinder block sub-assembly at the places shown in the illustration.

NOTICE:

Be careful not to damage the contact surfaces of the cylinder block sub-assembly and stiffening crankcase assembly.

HINT:

Tape the screwdriver tip before use.

63. REMOVE STRAIGHT SCREW PLUG

(a) Using a 10 mm hexagon socket wrench, remove the 3 straight screw plugs and 3 gaskets from the stiffening crankcase assembly.

64. REMOVE WIRE HARNESS CLAMP BRACKET

(a) Stiffening crankcase assembly side:

(1) Remove the bolt and wire harness clamp bracket from the stiffening crankcase assembly.

(b) Cylinder block sub-assembly side:

(1) Remove the bolt and wire harness clamp bracket from the cylinder block sub-assembly.

(c) Camshaft housing sub-assembly side:

(1) Remove the bolt and wire harness clamp bracket from the camshaft housing sub-assembly.

65. REMOVE STUD BOLT

NOTICE:

If a stud bolt is deformed or its threads are damaged, replace it.

66. REMOVE RING PIN

NOTICE:

It is not necessary to remove the ring pins unless they are being replaced.

67. REMOVE STRAIGHT PIN

NOTICE:

It is not necessary to remove the straight pins unless they are being replaced.

68. REMOVE REAR ENGINE OIL SEAL

(a) Remove the rear engine oil seal from the cylinder block sub-assembly.