CVVT and Camshaft Inspection

Continuously Variable Valve Timing (CVVT) Assembly

1. Inspect the CVVT for smooth rotation.
   1. Clamp the camshaft in a vise. Be careful not to damage the cam lobes and journals in the vise.
   2. Make sure the CVVT is locked by turning it clockwise or counterclockwise. It should not rotate.
   3. Intake CVVT: Seal one of the two advance oil holes in the camshaft journal with tape. Exhaust CVVT: Seal one of the two oil holes in the camshaft journal with tape. [Reception]

      

      [Exhaust]

      

   4. Intake CVVT: Apply approx. 150 kPa (1.5 kgf/cm², 21 psi) of compressed air to the unsealed advance hole to release the lock. Exhaust CVVT: Apply approx. 150 kPa (1.5 kgf/cm², 21 psi) of compressed air to the unsealed retard hole to release the lock.
   5. Intake CVVT: While applying compressed air, rotate the CVVT in the advance direction (counterclockwise) within its phase range, and make sure the CVVT rotates smoothly. Exhaust CVVT: While applying compressed air, rotate the CVVT in the retard direction (clockwise) and make sure the CVVT rotates smoothly. CVVT Phase Range Intake: 22.5°±1° (from most retarded position to most advanced position) Exhaust: 20°±1° (from most advanced position to most retarded position)

      

   6. Intake CVVT: Rotate the CVVT to the fully retarded position (clockwise), then make sure the CVVT is locked. Exhaust CVVT: Rotate the CVVT to the fully advanced position (counterclockwise), then make sure the CVVT is locked.

Camshaft

1. 1
   Inspect the cam lobes. Using a micrometer, measure the cam lobe height. Cam Lobe Height [Standard] Intake: 44.10 – 44.30 mm (1.7362 – 1.7440 in.) Exhaust: 44.90 – 45.10 mm (1.7677 – 1.7756 in.)

   

   If the cam lobe height is less than the standard value, replace the camshaft.
2. 2
   Inspect the camshaft journal oil clearance.

   1. Clean the camshaft bearing caps and journals.
   2. Install the camshafts on the cylinder head.
   3. Place a strip of Plastigage on each camshaft journal.

      

   4. Install the bearing caps.
   5. Remove the bearing caps.
   6. Measure the plastigage at its widest point. Camshaft Bearing Oil Clearance [Standard] Intake: No.1: 0.022 – 0.057 mm (0.00087 – 0.00224 in.) No.2, 3, 4, 5: 0.045 – 0.082 mm (0.00177 – 0.00323 in.) Exhaust: No.1: 0 – 0.032 mm (0 – 0.00126 in.) No.2, 3, 4, 5: 0.045 – 0.082 mm (0.00177 – 0.00323 in.) [Limit] Intake: No.1: 0.090 mm (0.00354 in.) No.2, 3, 4, 5: 0.120 mm (0.00472 in.) Exhaust: No.1: 0.090 mm (0.00354 in.) No.2, 3, 4, 5: 0.120 mm (0.00472 in.)

      

      If the oil clearance is greater than the maximum, replace the camshaft. If necessary, replace the cylinder head.
   7. Completely remove the plastigage.
   8. Remove the camshafts.
3. 3
   Inspect the camshaft end play.

   1. Install the camshafts.
   2. Using a dial indicator, measure the camshaft end play by moving the camshaft back and forth. Camshaft End Play [Standard]: 0.04 – 0.16 mm (0.0016 – 0.0063 in.) [Limit]: 0.20 mm (0.0078 in.)

      

      If the end play exceeds the limit, replace the camshaft. If necessary, replace the cylinder head.
   3. Remove the camshafts.

Exhaust Camshaft Bearing

1. 1
   Check the cylinder head bore identification mark. Cylinder head bore identification mark

   

   Cylinder Head Specifications

   Grade	Mark	Exhaust No.1 Cylinder Bore Diameter Head Hole
   a	A	40.000 – 40.008 mm (1.57480 – 1.5751 in.)
   D	B	40.008 - 40.016 mm (1.57511 - 1.57543 in.)
   c	C	40.016 - 40.021 mm (1.57543 - 1.57563 in.)

2. 2
   Select the camshaft bearing grade to match the cylinder head grade, as shown in the table below. Exhaust Camshaft Bearing Identification Mark

   

   Exhaust Camshaft Bearing Specifications

   Cylinder Head Bore Grade	Bearing grade for installation (color)	Bearing Thickness
   A (A)	C (green)	1.996 – 2.000 mm (0.07858 – 0.07874 in.)
   B (B)	B (no color)	2.000 – 2.004 mm (0.07874 – 0.07890 in.)
   C (C)	A (black)	2.004 - 2.008 mm (0.07890 - 0.07905 in.)

   
   

   Oil clearance: 0 - 0.032 mm (0 - 0.00126 in.)