Inspection [11/2021 - ]: Procedure

WARNING: This page is about a different car, the 2024 Lexus IS 500, 2023 Lexus IS 500, and 2022 Lexus IS 500. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT NO. 1 VALVE ROCKER ARM SUB-ASSEMBLY

Turn the roller by hand to check that it turns smoothly.

If the roller does not turn smoothly, replace the No. 1 valve rocker arm sub-assembly.

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INSPECT CAMSHAFT

Inspect the camshaft for runout.

Place the camshaft on V-blocks.

Using a dial indicator, measure the runout at the center journal.

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Maximum Runout

0.04 mm (0.00157 in.)

If the runout is more than the maximum, replace the camshaft.

HINT:

Check the oil clearance after replacing the camshaft.

See step 3

Using a micrometer, measure the cam lobe height.

Standard Cam Lobe Height

Item	Specified Condition
Intake	45.517 to 45.617 mm (1.79200 to 1.79594 in.)
Exhaust	44.602 to 44.702 mm (1.75598 to 1.75992 in.)

Minimum Cam Lobe Height

Item	Specified Condition
Intake	45.467 mm (1.79004 in.)
Exhaust	44.552 mm (1.75401 in.)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If the cam lobe height is less than the minimum, replace the camshaft.

Using a micrometer, measure the journal diameter.

Standard Journal Diameter

Item	Specified Condition
No. 1 journal	29.956 to 29.970 mm (1.17937 to 1.17992 in.)
Other journals	25.959 to 25.975 mm (1.02201 to 1.02264 in.)

If the journal diameter is not as specified, check the oil clearance.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

See step 4

INSPECT CAMSHAFT OIL CLEARANCE (for Bank 1)

Clean the camshaft bearing caps, camshaft housing LH and camshaft journals.
Place the camshafts on the camshaft housing LH.

Lay a strip of Plastigage across each camshaft journal.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Plastigage

Install the camshaft bearing caps.
See step 7

NOTE:
Do not turn the camshafts.
Remove the camshaft bearing caps.
See step 14

Measure the Plastigage at its widest point.

Standard Oil Clearance

Item	Specified Condition
No. 1 journal	0.030 to 0.069 mm (0.00118 to 0.00272 in.)
Other journals	0.025 to 0.062 mm (0.000984 to 0.00244 in.)

Maximum Oil Clearance

Item	Specified Condition
No. 1 journal	0.09 mm (0.00354 in.)
Other journals	0.09 mm (0.00354 in.)

If the oil clearance is more than the maximum, replace the camshaft.

If the oil clearance is still more than the maximum after replacing the camshaft, replace the camshaft housing LH.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	No. 1 Journal
*b	Plastigage

INSPECT CAMSHAFT OIL CLEARANCE (for Bank 2)

Clean the camshaft bearing caps, camshaft housing RH and camshaft journals.
Place the camshafts on the camshaft housing RH.

Lay a strip of Plastigage across each camshaft journal.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Plastigage

Install the camshaft bearing caps.
See step 3

NOTE:
Do not turn the camshafts.
Remove the camshaft bearing caps.
See step 18

Measure the Plastigage at its widest point.

Standard Oil Clearance

Item	Specified Condition
No. 1 journal	0.030 to 0.069 mm (0.00118 to 0.00272 in.)
Other journals	0.025 to 0.062 mm (0.000984 to 0.00244 in.)

Maximum Oil Clearance

Item	Specified Condition
No. 1 journal	0.09 mm (0.00354 in.)
Other journals	0.09 mm (0.00354 in.)

If the oil clearance is more than the maximum, replace the camshaft.

If the oil clearance is still more than the maximum after replacing the camshaft, replace the camshaft housing RH.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	No. 1 Journal
*b	Plastigage

INSPECT CAMSHAFT TIMING INTAKE GEAR ASSEMBLY

Using a vernier caliper, measure the width of the camshaft timing intake gear assembly eccentric shaft keyway.

Standard Width

6.02 to 6.11 mm (0.237 to 0.241 in.)

Maximum Width

6.7 mm (0.264 in.)

If the width is greater than the maximum, replace the camshaft timing intake gear assembly LH or camshaft timing intake gear assembly RH.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Keyway

Rotate the keyway of the camshaft timing intake gear assembly eccentric shaft by hand.
Standard

Rotates smoothly

If the result is not as specified, replace the camshaft timing intake gear assembly LH or camshaft timing intake gear assembly RH.
NOTE:
- Do not drop the camshaft timing intake gear assembly. If dropped, replace it.
- Do not disassemble the camshaft timing intake gear assembly. If disassembled, replace it.

INSPECT CAMSHAFT TIMING EXHAUST GEAR ASSEMBLY

Check the lock of the camshaft timing exhaust gear assembly.
1. Secure the camshaft in a vise between aluminum plates, and confirm that the camshaft timing exhaust gear assembly is locked.

Release the lock pin.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Open
*b	Close
*c	Advanced Side Path
*d	Retard Side Path

Cover the 4 paths of the cam journal with vinyl tape as shown in the illustration.
Make a hole in the tape on the advance side path and retard side path as shown in the illustration.

Apply approximately 200 kPa (2.0 kgf/cm² , 29 psi) of air pressure to the 2 open paths (the advance side path and the retard side path).

WARNING:

The lock pin is released and the camshaft timing exhaust gear assembly turns in the advance direction.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Advance Side Path
*b	Retard Side Path

Check that the camshaft timing exhaust gear assembly rotates in the retard direction when reducing the air pressure applied to the advance side path.

HINT:

This operation releases the lock pin for the most retarded position.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Advance Side Path
*b	Retard Side Path
*c	Hold Pressure
*d	Decompress

When the camshaft timing exhaust gear assembly reaches the most retard direction, release the air pressure from the advance side path, and then release the air pressure from the retard side path.
NOTE:
Do not release the air pressure from the retard side path first. The camshaft timing exhaust gear assembly may abruptly shift in the advance direction and break the lock pin.

Check for smooth rotation.
1. Turn the camshaft timing exhaust gear assembly within its movable range (18.5°) 2 or 3 times, but do not turn it to the most advanced position. Make sure that the camshaft timing exhaust gear assembly turns smoothly.
  NOTE:
  When the air pressure is released from the advance side path and then from the retard side path, the gear automatically returns to the most advanced position due to the advance assist spring operation and locks. Gradually release the air pressure from the retard side path before performing the smooth rotation check.
Check the lock at the most advanced position.
1. Confirm that the camshaft timing exhaust gear assembly locks at the most advanced position.

INSPECT CYLINDER HEAD SET BOLT

Using a vernier caliper, measure the diameter of the thread at the measurement point.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Measurement Point

Standard Diameter

10.85 to 11.00 mm (0.427 to 0.433 in.)

Minimum Diameter

10.6 mm (0.417 in.)

Measurement Point

for Intake Side Bolt

90 mm (3.54 in.)

for Exhaust Side Bolt

85 mm (3.35 in.)

HINT:

If the diameter is less than the minimum, replace the cylinder head set bolt. Failure to do so may lead to engine damage.
If there is any thread deformation, replace the cylinder head set bolt with a new one.

INSPECT NO. 1 CHAIN SUB-ASSEMBLY

Using a spring scale, pull the No. 1 chain sub-assembly with a force of 147 N (15 kgf, 33 lbf) and measure the length of the No. 1 chain sub-assembly using a vernier caliper.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a	Measurement Area

Maximum Chain Elongation

136.9 mm (5.39 in.)

HINT:

Perform the measurement at 3 random places.

If the elongation is more than the maximum, replace the No. 1 chain sub-assembly.

INSPECT NO. 2 CHAIN SUB-ASSEMBLY

Using a spring scale, pull the No. 2 chain sub-assembly with a force of 147 N (15 kgf, 33 lbf) and measure the length of the No. 2 chain sub-assembly using a vernier caliper.

Maximum Chain Elongation

137.6 mm (5.42 in.)

HINT:

Perform the measurement at 3 random places.

*a	Measurement Area

If the elongation is greater than the maximum, replace the No. 2 chain sub-assembly.

INSPECT CRANKSHAFT TIMING GEAR

Place the No. 1 chain sub-assembly around the crankshaft timing gear.

Using a vernier caliper, measure the sprocket diameter with the No. 1 chain sub-assembly.

Minimum Sprocket Diameter (with No. 1 Chain Sub-assembly)

61.4 mm (2.42 in.)

HINT:

The vernier caliper must contact the chain rollers when measuring.

If the diameter is less than the minimum, replace the No. 1 chain sub-assembly and crankshaft timing gear.

INSPECT CRANKSHAFT TIMING SPROCKET LH

Place the No. 1 chain sub-assembly around the crankshaft timing sprocket LH.

Using a vernier caliper, measure the sprocket diameter with the No. 1 chain sub-assembly.

Minimum Sprocket Diameter (with No. 1 Chain Sub-assembly)

61.4 mm (2.42 in.)

HINT:

The vernier caliper must contact the chain rollers when measuring.

If the diameter is less than the minimum, replace the No. 1 chain sub-assembly and crankshaft timing sprocket LH.

INSPECT NO. 1 CHAIN TENSIONER ASSEMBLY

Turn the stopper plate clockwise to release the lock. Push the plunger and check that it moves smoothly.

*a	Plunger
*b	Stopper Plate
*c	Moves Smoothly

If the plunger does not move smoothly, replace the No. 1 chain tensioner assembly LH or No. 1 chain tensioner assembly RH.

INSPECT NO. 2 CHAIN TENSIONER ASSEMBLY

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

*a Depth

*b Moves Smoothly
1. Check that the plunger moves smoothly.
2. Measure the depth of wear of the No. 2 chain tensioner assembly.
  Maximum Depth
  
  0.9 mm (0.0354 in.)
  
  If the depth is more than the maximum, replace the No. 2 chain tensioner assembly.
INSPECT NO. 3 CHAIN TENSIONER ASSEMBLY

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*a Depth

*b Moves Smoothly
1. Check that the plunger moves smoothly.
2. Measure the depth of wear of the No. 3 chain tensioner assembly.
  Maximum Depth
  
  0.9 mm (0.0354 in.)
  
  If the depth is more than the maximum, replace the No. 3 chain tensioner assembly.

INSPECT CHAIN TENSIONER SLIPPER

for Bank 1:

Depth

Measure the depth of wear of the chain tensioner slipper LH.
Maximum Depth

1.0 mm (0.0394 in.)

If the depth is more than the maximum, replace the chain tensioner slipper LH.

for Bank 2:

Depth

Measure the depth of wear of the chain tensioner slipper RH.
Maximum Depth

1.0 mm (0.0394 in.)

If the depth is more than the maximum, replace the chain tensioner slipper RH.

INSPECT CHAIN VIBRATION DAMPER

for Bank 1:

Depth

Measure the depth of wear of the chain vibration damper LH.
Maximum Depth

1.0 mm (0.0394 in.)

If the depth is more than the maximum, replace the chain vibration damper LH.

for Bank 2:

Depth

Measure the depth of wear of the chain vibration damper RH.
Maximum Depth

1.0 mm (0.0394 in.)

If the depth is more than the maximum, replace the chain vibration damper RH.