Cylinder Head: Inspection

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

INSPECT CYLINDER HEAD FOR WARPAGE

Using a precision straight edge and a feeler gauge, measure the surface contacting the cylinder block and the manifolds for warpage.

Maximum Warpage

ITEM SPECIFIED CONDITION CHART

Item	Specified Condition
Cylinder block side	0.08 mm (0.00315 in.)
Intake manifold side	0.08 mm (0.00315 in.)
Exhaust manifold side	0.08 mm (0.00315 in.)

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

Fig 1: Inspecting Cylinder Head For Warpage

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT CYLINDER HEAD FOR CRACKS
1. Using a dye penetrant, check the intake ports, exhaust ports and cylinder surface for cracks. If cracked, replace the cylinder head.

INSPECT CAMSHAFT THRUST CLEARANCE

Install the camshafts (See REASSEMBLY ).

Fig 2: Inspecting Cylinder Head For Cracks
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.

Standard Thrust Clearance

ITEM SPECIFIED CONDITION CHART

Item	Specified Condition
Intake	0.040 to 0.095 mm (0.00157 to 0.00374 in.)
Exhaust	0.090 to 0.145 mm (0.00354 to 0.00570 in.)

Maximum Thrust Clearance

ITEM SPECIFIED CONDITION CHART

Item	Specified Condition
Intake	0.110 mm (0.00433 in.)
Exhaust	0.150 mm (0.00591 in.)

Fig 3: Measuring Thrust Clearance

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If the thrust clearance is greater than the maximum, replace the cylinder head. If the thrust surface is damaged, replace the camshaft.

INSPECT CAMSHAFT OIL CLEARANCE

Clean the bearing caps and camshaft journals.
Place the camshafts on the cylinder head.
Lay a strip of Plastigage across each of the camshaft journals.
Install the bearing caps (See REASSEMBLY ).
NOTE: Do not turn the camshaft.
Remove the bearing caps (See DISASSEMBLY ).

Fig 4: Laying Strip Of Plastigage Across Camshaft Journals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the Plastigage at its widest point.

Standard Oil Clearance

ITEM SPECIFIED CONDITION CHART

Item	Specified Condition
Camshaft No. 1 journal bearing mark 1	0.007 to 0.038 mm (0.000276 to 0.00150 in.)
Camshaft No. 1 journal bearing mark 2	0.008 to 0.038 mm (0.000315 to 0.00150 in.)
Camshaft No. 1 journal bearing mark 3	0.008 to 0.038 mm (0.000315 to 0.00150 in.)
Camshaft other journals	0.025 to 0.062 mm (0.000984 to 0.00244 in.)
No. 2 camshaft No. 1 journal	0.040 to 0.072 mm (0.00157 to 0.00283 in.)
No. 2 camshaft other journals	0.025 to 0.062 mm (0.000984 to 0.00244 in.)

Fig 5: Measuring Plastigage At Widest Point

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Maximum Oil Clearance

ITEM SPECIFIED CONDITION CHART

Item	Specified Condition
Intake	0.070 mm (0.00276 in.)
Exhaust	0.100 mm (0.00394 in.)

NOTE: Completely remove the Plastigage after the inspection.

If the oil clearance is greater than the maximum, replace the camshaft. If necessary, replace the cylinder head.
If the oil clearance on the camshaft No. 1 journal is greater than the maximum, choose a new bearing and install it.

Check the number mark shown in the illustration.

Cylinder Head Journal Bore Diameter

CYLINDER HEAD JOURNAL BORE DIAMETER

Mark 1	Mark 2	Mark 3
40.000 to 40.009 mm (1.5748 to 1.5752 in.)	40.010 to 40.017 mm (1.5752 to 1.5755 in.)	40.018 to 40.025 mm (1.5755 to 1.5758 in.)

Standard Bearing Center Wall Thickness

STANDARD BEARING CENTER WALL THICKNESS

Mark 1	Mark 2	Mark 3
2.000 to 2.004 mm (0.0787 to 0.0789 in.)	2.005 to 2.008 mm (0.0789 to 0.0791 in.)	2.009 to 2.012 mm (0.0791 to 0.0792 in.)

Fig 6: Identifying Bearing Number Marks

Camshaft journal diameter:

35.971 to 35.985 mm (1.4162 to 1.4167 in.)

INSPECT INNER COMPRESSION SPRING
1. Using a vernier caliper, measure the free length of the valve spring.
  Free length:
  
  47.43 mm (1.867 in.)
  
  If the free length is not as specified, replace the valve spring.
  
  Fig 7: Measuring Free Length Of Valve Spring
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a steel set square, measure the deviation of the valve spring.
  Maximum deviation:
  
  1.6 mm (0.063 in.)
  
  If the deviation is greater than the maximum, replace the valve spring.
  
  Fig 8: Measuring Deviation Of Valve Spring
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT INTAKE VALVE
1. Using a gasket scraper, scrape off any carbon on the valve head.
  
  Fig 9: Scraping Carbon On Valve Head
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a vernier caliper, measure the overall length of the valve.
  Standard overall length:
  
  101.71 mm (4.0043 in.)
  
  Minimum overall length:
  
  101.21 mm (3.9846 in.)
  
  If the overall length is less than the minimum, replace the valve.
  
  Fig 10: Identifying Overall Length Of Valve
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Using a micrometer, measure the diameter of the valve stem.
  Valve stem diameter:
  
  5.470 to 5.485 mm (0.2154 to 0.2159 in.)
  
  If the valve stem is not as specified, check the oil clearance.
  
  Fig 11: Measuring Diameter Of Valve Stem
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Using a vernier caliper, measure the valve head margin thickness.
  Standard margin thickness:
  
  1.05 to 1.45 mm (0.0413 to 0.0571 in.)
  
  Minimum margin thickness:
  
  0.50 mm (0.0197 in.)
  
  If the margin thickness is less than the minimum, replace the valve.
  
  Fig 12: Identifying Valve Head Margin Thickness
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT EXHAUST VALVE
1. Using a gasket scraper, scrape off any carbon on the valve head.
  
  Fig 13: Scraping Carbon On Valve Head
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a vernier caliper, measure the overall length of the valve.
  Standard overall length:
  
  101.15 mm (3.9823 in.)
  
  Minimum overall length:
  
  100.70 mm (3.9646 in.)
  
  If the overall length is less than the minimum, replace the valve.
  
  Fig 14: Identifying Overall Length Of Valve
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Using a micrometer, measure the diameter of the valve stem.
  Valve stem diameter:
  
  5.465 to 5.480 mm (0.2152 to 0.2157 in.)
  
  If the valve stem is not as specified, check the oil clearance.
  
  Fig 15: Measuring Diameter Of Valve Stem
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Using a vernier caliper, measure the valve head margin thickness.
  Standard margin thickness:
  
  1.20 to 1.60 mm (0.0472 to 0.0630 in.)
  
  Minimum margin thickness:
  
  0.50 mm (0.0197 in.)
  
  If the margin thickness is less than the minimum, replace the valve.
  
  Fig 16: Identifying Valve Head Margin Thickness
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT INTAKE VALVE GUIDE BUSH
1. Using a caliper gauge, measure the inside diameter of the guide bush.
  Bushing inside diameter:
  
  5.510 to 5.530 mm (0.2169 to 0.2177 in.)
2. Subtract the valve stem diameter measurement from the guide bush inside diameter measurement.
  Standard oil clearance:
  
  0.025 to 0.060 mm (0.0010 to 0.0024 in.)
  
  Maximum oil clearance:
  
  0.090 mm (0.0035 in.)
  
  If the clearance is greater than the maximum, replace the valve and guide bush.
  
  Fig 17: Measuring Inside Diameter Of Guide Bush
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT EXHAUST VALVE GUIDE BUSH
1. Using a caliper gauge, measure the inside diameter of the guide bush.
  Bushing inside diameter:
  
  5.510 to 5.530 mm (0.2169 to 0.2177 in.)
2. Subtract the valve stem diameter measurement from the guide bushing inside diameter measurement.
Fig 18: Measuring Inside Diameter Of Guide Bush
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard oil clearance:

0.030 to 0.065 mm (0.0012 to 0.0026 in.)

Maximum oil clearance:

0.095 mm (0.0037 in.)

If the clearance is greater than the maximum, replace the valve and guide bush.
INSPECT VALVE LIFTER
1. Using a micrometer, measure the lifter diameter.
  Lifter diameter:
  
  30.966 to 30.976 mm (1.2191 to 1.2195 in.)
  
  Fig 19: Measuring Lifter Diameter
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a caliper gauge, measure the lifter bore diameter of the cylinder head.
  Standard lifter bore diameter:
  
  31.009 to 31.025 mm (1.2208 to 1.2215 in.)
3. Subtract the lifter diameter measurement from the lifter bore diameter measurement.
  Standard oil clearance:
  
  0.033 to 0.059 mm (0.00130 to 0.00232 in.)
  
  Maximum oil clearance:
  
  0.079 mm (0.00311 in.)
  
  If the oil clearance is greater than the maximum, replace the lifter. If necessary, replace the cylinder head.
  
  Fig 20: Measuring Lifter Bore Diameter Of Cylinder Head
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT CYLINDER HEAD SET BOLT
1. Using a vernier caliper, measure the length of the head bolts from the seat to the end.
  Standard bolt length:
  
  141.3 to 142.7 mm (5.563 to 5.618 in.)
  
  Maximum bolt length:
  
  144.2 mm (5.677 in.)
  
  If the bolt length is greater than the maximum, replace the cylinder head set bolt.
  
  Fig 21: Identifying Length Of Head Bolts
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002