Cylinder Head: Inspection

WARNING: This page is about a different variant/trim than selected.

INSPECT CYLINDER HEAD SUB-ASSEMBLY

Using a precision straightedge and feeler gauge, measure the warpage of the contact surfaces where the cylinder head contacts the cylinder block and manifold.

Maximum Warpage

ITEM SPECIFIED CONDITION CHART

Item	Specified Condition
Cylinder head lower side	0.05 mm (0.00197 in.)
Intake manifold side	0.10 mm (0.00394 in.)
Exhaust manifold side	0.10 mm (0.00394 in.)

If the warpage is more than the maximum, replace the cylinder head.

Fig 1: Measuring Warpage Of Cylinder Head Contact Surfaces

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Using a dye penetrant, check the intake ports, exhaust ports and cylinder surface for cracks. If cracked, replace the cylinder head.

Fig 2: Checking Intake Ports, Exhaust Ports And Cylinder Surface For Cracks

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT COMPRESSION SPRING
1. Using a vernier caliper, measure the free length of the inner compression spring.
  Standard free length:
  
  50.0 mm (1.97 in.)
  
  If the free length is not as specified, replace the spring.
  
  Fig 3: Measuring Free Length Of Inner Compression Spring
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a steel square, measure the deviation of the inner compression spring.
  Maximum deviation:
  
  1.0 mm (0.0394 in.)
  
  Maximum angle:
  
  2°
  
  If the deviation is more than the maximum, replace the spring.
  
  Fig 4: Measuring Deviation Of Inner Compression Spring
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT INTAKE VALVE
1. Using a micrometer, measure the diameter of the valve stem.
  Standard valve stem diameter:
  
  5.470 mm to 5.485 mm (0,2154 to 0.2159 in.)
  
  Fig 5: Measuring Diameter Of Valve Stem
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a vernier caliper, measure the valve head margin thickness.
  Standard margin thickness:
  
  1.0 mm (0.0394 in.)
  
  Minimum margin thickness:
  
  0.50 mm (0.0197 in.)
  
  If the margin thickness is less than the minimum, replace the valve.
  
  Fig 6: Measuring Valve Head Margin Thickness
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Using a vernier caliper, measure the overall length of the valve.
  Standard overall length:
  
  103.92 mm (4.09 in.)
  
  Minimum overall length:
  
  103.42 mm (4.07 in.)
  
  If the overall length is less than the minimum, replace the intake valve.
  
  Fig 7: Measuring Overall Length Of Valve
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT EXHAUST VALVE
1. Using a micrometer, measure the diameter of the valve stem.
  Standard valve stem diameter:
  
  5.465 mm to 5.480 mm (0.2152 to 0.2157 in.)
  
  Fig 8: Measuring Diameter Of Valve Stem
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a vernier caliper, measure the valve head margin thickness.
  Standard margin thickness:
  
  1.0 mm (0.0394 in.)
  
  Minimum margin thickness:
  
  0.50 mm (0.0197 in.)
  
  If the margin thickness is less than the minimum, replace the exhaust valve.
  
  Fig 9: Measuring Valve Head Margin Thickness
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Using a vernier caliper, measure the overall length of the valve.
  Standard overall length:
  
  112.91 mm (4.44 in.)
  
  Minimum overall length:
  
  112.41 mm (4.43 in.)
  
  If the overall length is less than the minimum, replace the exhaust valve.
  
  Fig 10: Measuring Overall Length Of Valve
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT VALVE GUIDE BUSH OIL CLEARANCE

Using a caliper gauge, measure the inside diameter of the guide bush.
Standard bush inside diameter: 5.510 to 5.530 mm (0.2169 to 0.2177 in.)

Subtract the valve stem diameter measurement from the guide bush inside diameter measurement.

Standard Oil Clearance

ITEM SPECIFIED CONDITION CHART

Item	Specified Condition
Intake	0.025 to 0.060 mm (0.000984 to 0.00236 in.)
Exhaust	0.030 to 0.065 mm (0.00118 to 0.00256 in.)

Fig 11: Measuring Inside Diameter Of Guide Bush

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Maximum Oil Clearance

ITEM SPECIFIED CONDITION CHART

Item	Specified Condition
Intake	0.08 mm (0.00315 in.)
Exhaust	0.10 mm (0.00394 in.)

If the oil clearance is more than the maximum, replace the valve and guide bush.

INSPECT INTAKE VALVE SEAT
1. Apply a light coat of Prussian blue to the valve face.
2. Lightly press the valve face against the valve seat.
  HINT:
  
  Do not rotate the valve while pressing the valve.
3. Check the valve face and valve seat.
  1. Check that the contact surfaces of the valve seat and valve face are in the middle area of their respective surfaces, with the width between 1.1 and 1.5 mm (0.0433 and 0.0591 in.).
    If not, correct the valve seat.
    
    Fig 12: Inspecting Intake Valve Seat
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. Check that the contact surfaces of the valve seat and valve face are even around the entire valve seat.
    If not, correct the valve seat.
INSPECT EXHAUST VALVE SEAT
1. Apply a light coat of Prussian blue to the valve face.
2. Lightly press the valve face against the valve seat.
  HINT:
  
  Do not rotate the valve while pressing the valve.
3. Check the valve face and valve seat.
  1. Check that the contact surfaces of the valve seat and valve face are in the middle area of their respective surfaces, with the width between 1.1 and 1.5 mm (0.0433 and 0.0591 in.).
    If not, correct the valve seat.
  2. Check that the contact surfaces of the valve seat and valve face are even around the entire valve seat.
    If not, correct the valve seat.
Fig 13: Inspecting Exhaust Valve Seat
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT CAMSHAFT OIL CLEARANCE

NOTE: Do not turn the camshafts.

Clean the bearing caps, camshaft housing and camshaft journals.
Place the camshafts on the camshaft housing.
Lay a strip of Plastigage across each of the camshaft journals.
Install the camshaft bearing caps (See CYLINDER HEAD GASKET ).
Install the camshaft housing sub-assembly (See CYLINDER HEAD GASKET ).
Remove the camshaft bearing caps (See INSTALLATION ).

Fig 14: Inspecting Camshaft Oil Clearance
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the Plastigage at its widest point.

Standard Oil Clearance

ITEM SPECIFIED CONDITION CHART

Item	Specified Condition
Intake No. 1 journal	0.035 to 0.072 mm (0.00137 to 0.00283 in.)
Exhaust No. 1 journal	0.049 to 0.086 mm (0.00193 to 0.00339 in.)
Other journal	0.025 to 0.062 mm (0.000984 to 0.00244 in.)

Maximum Oil Clearance

ITEM SPECIFIED CONDITION CHART

Item	Specified Condition
Intake No. 1 journal	0.085 mm (0.00335 in.)
Exhaust No. 1 journal	0.095 mm (0.00374 in.)
Other journal	0.085 mm (0.00335 in.)

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

Fig 15: Measuring Oil Clearance Using Plastigage

INSPECT CAMSHAFT THRUST CLEARANCE
1. Inspect the intake camshaft.
  1. Install the intake camshaft.
  2. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.
    If the thrust clearance is more than the maximum, replace the camshaft housing. If the thrust surface is damaged, replace the camshaft.
2. Inspect the intake and exhaust camshafts.
  1. Install the intake and exhaust camshafts.
  2. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.
    Standard Thrust Clearance:
    
    0.060 to 0.155 mm (0.00236 to 0.00610 in.)
    
    Maximum Thrust Clearance:
    
    0.170 mm (0.00669 in.)
    
    If the thrust clearance is more than the maximum, replace the camshaft housing. If the thrust surface is damaged, replace the camshaft.

Fig 16: Measuring Thrust Clearance