Cylinder Head: Inspection

1. Using a precision straightedge and a feeler gauge, measure the surfaces contacting the cylinder block and the manifolds for warpage.

   Maximum Warpage 

   ITEM SPECIFICATION
   
   

   Item	Specified Condition
   Cylinder block side	0.05 mm (0.0020 in.)
   Intake manifold side	0.10 mm (0.0039 in.)
   Exhaust manifold side	0.10 mm (0.0039 in.)

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

   Fig 1: Inspecting Cylinder Head For Flatness

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Fig 2: Inspecting Cylinder Head For Cracks

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Apply a light coat of Prussian blue to the valve face.
2. Lightly press the valve face against the valve seat.
3. Check the valve face and valve seat according to the following procedure:

Fig 3: Identifying Valve Seats Width

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. If Prussian blue appears 360° around the valve face, the valve face is concentric. If not, replace the valve.
2. If Prussian blue appears 360° around the valve seat, the guide and valve face are concentric. If not, resurface the valve seat.
3. Check that the valve seat contact is in the middle of the valve face with the valve seat width between 1.0 and 1.4 mm (Intake side (0.039 to 0.055 in.)).
4. Check that the valve seat contact is in the middle of the valve face with the valve seat width between 1.0 and 1.4 mm (Exhaust side (0.039 to 0.055 in.)).

1. Install the camshafts (See INSTALLATION ).
2. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.

   Standard Thrust Clearance 

   STANDARD THRUST CLEARANCE CHART
   
   

   Item	Specified Condition
   Intake	0.06 to 0.155 mm (0.0024 to 0.0061 in.)
   Exhaust	0.06 to 0.155 mm (0.0024 to 0.0061 in.)

   Maximum Thrust Clearance 

   THRUST CLEARANCE CHART
   
   

   Item	Specified Condition
   Intake	0.17 mm (0.0067 in.)
   Exhaust	0.17 mm (0.0067 in.)

   Fig 4: Measuring Thrust Clearance Of Camshaft

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

1. Clean the bearing caps and camshaft journals.
2. Place the camshafts on the camshaft housing.
3. Lay a strip of Plastigage across each of the camshaft journals.
4. Install the bearing caps (See INSTALLATION ).
   NOTE: Do not turn the camshaft.
   Fig 5: Inspecting Camshaft Oil Clearance

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. Remove the bearing caps (See REMOVAL ).
6. Measure the Plastigage at its widest point.

   Standard Oil Clearance 

   ITEM SPECIFICATION
   
   

   Item	Specified Condition
   Camshaft No. 1 journal	0.030 to 0.063 mm (0.0012 to 0.0025 in.)
   Camshaft other journals	0.035 to 0.072 mm (0.0014 to 0.0028 in.)

   Fig 6: Measuring Plastigage Widest Point

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Maximum Oil Clearance 

   ITEM SPECIFICATION
   
   

   Item	Specified Condition
   Camshaft No. 1 journal	0.085 mm (0.0033 in.)
   Camshaft other journals	0.09 mm (0.0035 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.

1. Using a vernier caliper, measure the free length of the valve spring.

   Free length: 

   53.36 mm (2.1008 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 square, measure the deviation of the valve spring.

   Maximum deviation: 

   1.0 mm (0.0394 in.) 

   If the deviation is greater than the maximum, replace the valve spring.

   Fig 8: Identifying Deviation Of Valve Spring

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Using a gasket scraper and wire brush, scrape off any carbon on the valve head.
   Fig 9: Inspecting Intake Valve

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a vernier caliper, measure the overall length of the valve.

   Standard overall length: 

   109.34 mm (4.3047 in.) 

   Minimum overall length: 

   108.84 mm (4.2850 in.) 

   If the overall length is less than the minimum, replace the valve.

   Fig 10: Identifying Valve Length

   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 diameter 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: 

   1.0 mm (0.0394 in.) 

   Minimum margin thickness: 

   0.5 mm (0.0197 in.) 

   If the margin thickness is less than the minimum, replace the valve.

   Fig 12: Measuring Valve Head Margin Thickness

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Using a gasket scraper and wire brush, scrape off any carbon on the valve head.
   Fig 13: Inspecting Intake Valve

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a vernier caliper, measure the overall length of the valve.

   Standard overall length: 

   108.25 mm (4.2618 in.) 

   Minimum overall length: 

   107.75 mm (4.2421 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 diameter 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: 

   1.01 mm (0.0398 in.) 

   Minimum margin thickness: 

   0.5 mm (0.0197 in.) 

   If the margin thickness is less than the minimum, replace the valve.

   Fig 16: Measuring Valve Head Margin Thickness

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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.

Fig 17: Measuring Inside Diameter Of Guide Bush

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Standard Oil Clearance 

Maximum Oil Clearance 

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