Cylinder Head: Inspection

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INSPECT CYLINDER HEAD SUB-ASSEMBLY

Clean the cylinder head.
1. Using a gasket scraper, remove all the gasket material from the cylinder block contact surface.
  NOTE: Be careful not to scratch the cylinder block contact surface.
  
  Fig 1: Removing Gasket Material From Cylinder Block Contact Surface
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a wire brush, remove all the carbon from the combustion chambers.
  NOTE: Be careful not to scratch the cylinder block contact surface.
  
  Fig 2: Removing Carbon From Combustion Chambers
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Using a valve guide bushing brush and solvent, clean all the guide bushes.
  
  Fig 3: Cleaning Guide Bushes
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Using a soft brush and solvent, thoroughly clean the cylinder head.
  
  Fig 4: Cleaning Cylinder Head
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Inspect for flatness.

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

Fig 5: Measuring Cylinder Block Surfaces

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Maximum warpage

MAXIMUM WARPAGE

Item	Specified Condition
Cylinder block surface	0.10 mm (0.0039 in.)
Intake manifold surface	0.10 mm (0.0039 in.)
Exhaust manifold surface	0.10 mm (0.0039 in.)

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

Inspect the cylinder head for cracks.
1. Using a dye penetrant, check the combustion chamber, intake ports, exhaust ports and cylinder block surface for cracks.
  If the cylinder head is cracked, replace it.
  
  Fig 6: Inspecting Cylinder Head For Cracks
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

REMOVE EXHAUST MANIFOLD SUB-ASSEMBLY LH
1. Using a precision straightedge and feeler gauge, measure the surface contacting the cylinder head for warpage.
  Maximum warpage: 0.50 mm (0.0197 in.)
  
  If the warpage is greater than the maximum, replace the manifold.
  
  Fig 7: Removing Exhaust Manifold Sub-Assembly LH
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
REMOVE EXHAUST MANIFOLD SUB-ASSEMBLY RH
1. Using a precision straightedge and feeler gauge, measure the surface contacting the cylinder head for warpage.
  Maximum warpage: 0.50 mm (0.0197 in.)
  
  If the warpage is greater than the maximum, replace the manifold.
  
  Fig 8: Removing Exhaust Manifold Sub-Assembly RH
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT INTAKE VALVE GUIDE BUSH
1. 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.)
  
  If the diameter is not as specified, check the oil clearance.
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: 0.08 mm (0.0031 in.)
  If the clearance is greater than the maximum, replace the valve and guide bush.
Fig 9: Inspecting Intake Valve 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.
  Standard bush inside diameter: 5.510 to 5.530 mm (0.2169 to 0.2177 in.)
  
  If the diameter is not as specified, check the oil clearance.
2. Subtract the valve stem diameter measurement from the guide bush inside diameter measurement.
  - Standard oil clearance: 0.030 to 0.065 mm (0.0012 to 0.0026 in.)
  - Maximum oil clearance: 0.10 mm (0.0039 in.)
  If the clearance is greater than the maximum, replace the valve and guide bush.
  
  Fig 10: Inspecting Exhaust Valve Guide Bush
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT INTAKE VALVE
1. Clean the valves.
  1. Using a gasket scraper, chip off any carbon from the valve head.
  2. Using a wire brush, thoroughly clean the valve.
    
    Fig 11: Cleaning Valve
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a micrometer, measure the diameter of the valve stem.
  Standard valve stem diameter: 5.470 to 5.485 mm (0.2154 to 0.2159 in.)
  
  If the diameter is greater than the maximum, replace the valve and guide bush.
  
  Fig 12: Measuring Diameter Of Valve Stem
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Check the valve face angle.
  1. Grind the valve sufficiently to remove pits and carbon.
  2. Check that the valve is ground to the correct valve face angle.
    Standard valve face angle: 44.5°
    
    If the valve face is worn, replace the valve.
    
    Fig 13: Checking Valve Face Angle
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Check the valve head margin thickness.
  - Standard margin thickness: 1.00 mm (0.039 in.)
  - Minimum margin thickness: 0.5 mm (0.020 in.)
  If the margin thickness is less than the minimum, replace the valve.
  
  Fig 14: Checking Valve Head Margin Thickness
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. Check the valve overall length.
  - Standard overall length: 95.05 mm (3.7421 in.)
  - Minimum overall length: 94.55 mm (3.7224 in.)
  If the overall length is less than the minimum, replace the valve.
  
  Fig 15: Identifying Valve Overall Length
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
6. Check the surface of the valve stem tip for wear. If the valve stem tip is worn, resurface the tip with a grinder or replace the valve.
  NOTE: Be careful not to grind off more than the minimum.
  
  Fig 16: Checking Surface Of Valve Stem Tip For Wear
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT EXHAUST VALVE
1. Clean the valves.
  1. Using a gasket scraper, chip off any carbon from the valve head.
  2. Using a wire brush, thoroughly clean the valve.
    
    Fig 17: Cleaning Valves
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a micrometer, measure the diameter of the valve stem.
  Standard valve stem diameter: 5.465 to 5.480 mm (0.2152 to 0.2157 in.)
  
  If the clearance is greater than the maximum, replace the valve and guide bush.
  
  Fig 18: Measuring Diameter Of Valve Stem
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Check the valve face angle.
  1. Grind the valve sufficiently to remove pits and carbon.
  2. Check that the valve is ground to the correct valve face angle.
    Standard valve face angle: 44.5°
    
    If the valve face is worn, replace the valve.
    
    Fig 19: Checking Valve Face Angle
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Check the valve head margin thickness.
  - Standard margin thickness: 1.0 mm (0.039 in.)
  - Minimum margin thickness: 0.5 mm (0.020 in.)
  If the margin thickness is less than the minimum, replace the valve.
  
  Fig 20: Checking Valve Head Margin Thickness
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. Check the overall valve length.
  - Standard overall length: 95.10 mm (3.7441 in.)
  - Minimum overall length: 94.60 mm (3.7244 in.)
  If the overall length is less than the minimum, replace the valve.
  
  Fig 21: Identifying Overall Valve Length
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
6. Check the surface of the valve stem tip for wear. If the valve stem tip is worn, resurface the tip with a grinder or replace the valve.
  NOTE: Be careful not to grind off more than the minimum.
  
  Fig 22: Checking Surface Of Valve Stem Tip For Wear
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT VALVE SPRING
1. Using steel squares, measure the deviation of the spring.
  Maximum deviation: 2.0 mm (0.079 in.)
  
  If the deviation is greater than the maximum, replace the spring.
  
  Fig 23: Measuring Deviation Of Spring Using Steel Squares
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a vernier caliper, measure the free length of the spring.
  Standard free length: 54.1 mm (2.130 in.)
  
  If the free length is not as specified, replace the spring.
  
  Fig 24: Measuring Free Length Of Spring Using Vernier Caliper
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Using a spring tester, measure the tension of the valve spring at the specified installed length.
  Standard installed tension:
  
  210 to 226 N (21.4 to 23.0 kgf, 47.2 to 50.7 lbf) at 35.0 mm (1.378 in.)
  
  If the installed tension is not as specified, replace the valve spring.
  
  Fig 25: Measuring Tension Of Valve Spring
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT INTAKE VALVE SEAT
1. Using a 45° carbon cutter, resurface the valve seats.
  HINT:
  
  Only remove the amount of metal necessary to clean the seats.
  
  Fig 26: Resurfacing Valve Seats Using Carbon Cutter
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check the valve seating position.
  1. Apply a light coat of Prussian blue (or white lead) to the valve face.
  2. Lightly press the valve against the seat. Do not rotate the valve.
    
    Fig 27: Checking Valve Seating Position
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Check the valve face and seat for the following:
  1. If blue appears 360° around the face, the valve is concentric. If not, replace the valve.
  2. If blue appears 360° around the valve seat, the guide and face are concentric. If not, resurface the seat.
  3. Check that the seat contact is in the middle of the valve face and has the following width.
    Standard width: 1.0 to 1.4 mm (0.039 to 0.055 in.)
    
    If not, correct the intake valve seats as follows:
4. If the seating is too high on the valve face: Use 30° and 45° cutters to correct the seat.
  
  Fig 28: Using 30° & 45° Cutters To Correct Seat (Seating Too High)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. If the seating is too low on the valve face: Use 60° and 45° cutters to correct the seat.
  
  Fig 29: Using 60° & 45° Cutters To Correct Seat (Seating Too Low)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
6. Hand rub the valve and valve seat with an abrasive compound.
7. After hand rubbing, clean the valve and valve seat.
Fig 30: Cleaning Valve & Valve Seat
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT EXHAUST VALVE SEAT
1. Using a 45° carbon cutter, resurface the valve seats.
  HINT:
  
  Only remove the amount of metal necessary to clean the seats.
  
  Fig 31: Resurfacing Valve Seats Using 45° Carbon Cutter
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check the valve seating position.
  1. Apply a light coat of Prussian blue (or white lead) to the valve face.
  2. Lightly press the valve against the seat. Do not rotate the valve.
3. Check the valve face and seat for the following:
  1. If blue appears 360° around the face, the valve is concentric. If not, replace the valve.
  2. If blue appears 360° around the valve seat, the guide and face are concentric. If not, resurface the seat.
  3. Check that the seat contact is in the middle of the valve face and has the following width.
    Standard width: 1.0 to 1.4 mm (0.039 to 0.055 in.)
    
    If not, correct the exhaust valve seats as follows:
  Fig 32: Checking Valve Face & Seat
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. If the seating is too high on the valve face: Use 30° and 45° cutters to correct the seat.
  
  Fig 33: Using 30° & 45° Cutters To Correct Seat (Seating Too High)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. If the seating is too low on the valve face: Use 60° and 45° cutters to correct the seat.
  
  Fig 34: Using 60° & 45° Cutters To Correct Seat (Seating Too Low)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
6. Hand rub the valve and valve seat with an abrasive compound.
7. After hand rubbing, clean the valve and valve seat.
Fig 35: Cleaning Valve & Valve Seat
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT VALVE LIFTER
1. Using a micrometer, measure the lifter diameter at a position 12.3 to 12.7 mm (0.484 to 0.500 in.) from the top surface.
  Standard lifter diameter: 30.968 to 30.976 mm (1.2192 to 1.2195 in.)
  
  If the lifter diameter is not as specified, check the oil clearance.
  
  Fig 36: Measuring Lifter Diameter Using Micrometer
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a caliper gauge, measure the lifter bore diameter of the cylinder head.
  Standard lifter bore diameter: 31.000 to 31.016 mm (1.2205 to 1.2211 in.)
  
  If the lifter diameter is not as specified, check the oil clearance.
  
  Fig 37: Measuring Lifter Bore Diameter Of Cylinder Head Using Caliper Gauge
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Subtract the lifter diameter measurement from the lifter bore diameter measurement.
  - Standard oil clearance: 0.024 to 0.050 mm (0.0009 to 0.0020 in.)
  - Maximum oil clearance: 0.07 mm (0.0028 in.)
  If the oil clearance is greater than the maximum, replace the lifter. If necessary, replace the cylinder head.

INSPECT NO. 1 CAMSHAFT

Inspect the circle runout.
1. Place the camshaft on V-blocks.
2. Using a dial indicator, measure the circle runout at the center journal.
  Maximum circle runout: 0.03 mm (0.0012 in.)
  
  If the circle runout is greater than the maximum, replace the No. 1 camshaft.
  
  Fig 38: Inspecting Circle Runout
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Using a micrometer, measure the cam lobe height.
- Standard cam lobe height: 42.61 to 42.71 mm (1.6776 to 1.6815 in.)
- Minimum cam lobe height: 42.46 mm (1.6717 in.)
If the cam lobe height is less than the minimum, replace the No. 1 camshaft.

Fig 39: Measuring Cam Lobe Height
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Inspect the journal diameter of the camshaft.
1. Using a micrometer, measure the journal diameter of the camshaft for the camshaft bearing.
  Standard journal diameter: 26.954 to 26.970 mm (1.0612 to 1.0618 in.)
  
  If the journal diameter is not as specified, check the oil clearance.
  
  Fig 40: Measuring Journal Diameter Of Camshaft For Camshaft Bearing
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a micrometer, measure the journal diameter for the camshaft timing tube.
  Standard journal diameter: 30.984 to 31.000 mm (1.2198 to 1.2205 in.)
  
  If the journal diameter is not as specified, check the oil clearance.
  
  Fig 41: Measuring Journal Diameter For Camshaft Timing Tube
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Inspect the journal diameter of the camshaft timing tube.
1. Using a micrometer, measure the journal diameter.
  Standard journal diameter: 39.955 to 39.964 mm (1.5730 to 1.5734 in.)
  
  If the journal diameter is not as specified, check the oil clearance.
2. Install the drive gear to the camshaft timing tube.
  
  Fig 42: Measuring Journal Diameter
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Install the camshaft timing tube to the camshaft, and check that the timing tube turns smoothly.
If necessary, replace the timing tube and camshaft.

Fig 43: Checking Timing Tube Turns Smoothly
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check the oil clearance.

Clean the bearing caps and journals.
Check the bearings for flaking and scoring. If the bearings are damaged, replace the bearing caps and cylinder head as a set.
Place the No. 1 camshaft on the cylinder head.
Lay a strip of Plastigage across each of the journals.

Fig 44: Laying Strip Of Plastigage Across Each Of Journals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Install the bearing caps.
NOTE: Be careful not to turn the No. 1 camshaft.
Remove the bearing caps.

Measure the Plastigage at its widest point.

Standard oil clearance

STANDARD OIL CLEARANCE

Journal Position	Specified Condition
Camshaft journal	0.030 to 0.071 mm (0.0012 to 0.0028 in.)
Camshaft timing tube journal	0.036 to 0.057 mm (0.0014 to 0.0022 in.)

Maximum oil clearance

MAXIMUM OIL CLEARANCE

Journal Position	Specified Condition
Camshaft journal	0.100 mm (0.0039 in.)
Camshaft timing tube journal	0.075 mm (0.0030 in.)

If the oil clearance is greater than the maximum, replace the camshaft and timing tube. If necessary, replace the bearing caps and cylinder head as a set.

Fig 45: Measuring Plastigage At Its Widest Point