CYLINDER HEAD(w/o Glow Plug Controller) INSPECTION

PROCEDURE

1. INSPECT CYLINDER HEAD SUB-ASSEMBLY

   1. Inspect cylinder head sub-assembly warpage.

      1. Using a precision straightedge and feeler gauge, measure the warpage on the cylinder block sub-assembly side, the intake side and exhaust side.

         

         *a	Cylinder Block Sub-assembly Side	*b	Exhaust Side
         *c	Intake Side	-	-

         Maximum Warpage

         Surface	Specified Condition
         Cylinder block sub-assembly side	0.08 mm (0.00315 in.)
         Intake side	0.20 mm (0.00787 in.)
         Exhaust side	0.20 mm (0.00787 in.)

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

   2. Inspect for cracks.

      1. 

         Using a dye penetrant, check the combustion chambers, intake ports, exhaust ports and the cylinder block sub-assembly contact surface for cracks.

         If cracked, replace the cylinder head sub-assembly.

2. INSPECT VALVE SEAT

   1. 

      *a

      Width

      Apply a light coat of Prussian blue to each valve face.

   2. Lightly press the valve face against the valve seat.

      Note:

      Do not rotate the valve.

   3. Remove the valve from the cylinder head sub-assembly.

      1. If Prussian blue appears 360° around the face, the valve is concentric. If not, replace the valve.

      2. If Prussian blue appears 360° around the valve seat, the guide and 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 following width.

         Standard width

         Intake

         1.0 to 1.2 mm (0.0394 to 0.0472 in.)

         Exhaust

         1.2 to 1.6 mm (0.0472 to 0.0630 in.)

3. INSPECT CAMSHAFT OIL CLEARANCE

   1. Clean the camshaft and camshaft bearing caps.

   2. 

      *a	Plastigage

      Place the camshaft on the cylinder head sub-assembly.

   3. Lay a strip of Plastigage across each camshaft journal.

   4. Install the bearing caps.

      Click here

      Note:

      Do not turn the camshaft when measuring.

   5. Remove the bearing caps.

      Click here

   6. 

      Measure the Plastigage at its widest point.

      Standard oil clearance

      0.037 to 0.073 mm (0.00146 to 0.00287 in.)

      Maximum oil clearance

      0.10 mm (0.00394 in.)

      Note:

      Completely remove the Plastigage after the inspection.

      If the clearance is greater than the maximum, replace the camshaft. If necessary, replace the cylinder head sub-assembly.

4. INSPECT CAMSHAFT THRUST CLEARANCE

   1. Install the camshaft.

      Click here

   2. Install the camshaft timing sprocket to the camshaft.

      Click here

   3. 

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

      Standard thrust clearance

      0.040 to 0.090 mm (0.00157 to 0.00354 in.)

      Maximum thrust clearance

      0.25 mm (0.00984 in.)

      If the thrust clearance is greater than the maximum, replace the cylinder head sub-assembly or camshaft.

5. INSPECT INTAKE VALVE

   1. 

      *a	Overall Length

      Using a vernier caliper, measure the overall length of the intake valve.

      Standard overall length

      99.69 to 100.29 mm (3.9248 to 3.9484 in.)

      Minimum overall length

      99.19 mm (3.9051 in.)

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

   2. 

      *a	Valve Stem

      Using a micrometer, measure the valve stem diameter.

      Standard valve stem diameter

      5.970 to 5.985 mm (0.2350 to 0.2356 in.)

   3. 

      *a	Margin Thickness

      Using a vernier caliper, measure the valve head margin thickness.

      Standard margin thickness

      1.2 mm (0.0472 in.)

      Minimum margin thickness

      0.6 mm (0.0236 in.)

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

6. INSPECT EXHAUST VALVE

   1. 

      *a	Overall Length

      Using a vernier caliper, measure the overall length of the exhaust valve.

      Standard overall length

      99.39 to 99.99 mm (3.9130 to 3.9367 in.)

      Minimum overall length

      98.89 mm (3.8933 in.)

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

   2. 

      *a	Valve Stem

      Using a micrometer, measure the valve stem diameter.

      Standard valve stem diameter

      5.965 to 5.980 mm (0.2348 to 0.2354 in.)

   3. 

      *a	Margin Thickness

      Using a vernier caliper, measure the valve head margin thickness.

      Standard margin thickness

      1.5 mm (0.0591 in.)

      Minimum margin thickness

      0.7 mm (0.0276 in.)

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

7. INSPECT OUTER COMPRESSION SPRING

   1. 

      Using a vernier caliper, measure the free length of the outer compression spring.

      Standard free length

      42.17 mm (1.6602 in.)

      If the free length is not as specified, replace the outer compression spring.

   2. 

      *a

      Deviation

      Using a steel square, measure the deviation of the outer compression spring.

      Maximum deviation

      1.5 mm (0.0591 in.)

      If the deviation is greater than the maximum, replace the outer compression spring.

8. INSPECT VALVE GUIDE BUSH OIL CLEARANCE

   1. 

      Using a caliper gauge, measure the inside diameter of the valve guide bush.

      Standard bush inside diameter

      6.010 to 6.030 mm (0.2367 to 0.2374 in.)

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

      Standard Oil Clearance

      Guide Bush	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.)

      Maximum Oil Clearance

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

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