Cylinder Head - Inspection

1. Clean cylinder block sub-assembly

2. Check cylinder block for warpage

3. Clean cylinder head sub-assembly

4. Check cylinder head for warpage

5. Inspect cylinder head set bolt

​

1. Turn the crankshaft, and bring each piston to the top dead center (TDC). Using a gasket scraper, remove all the carbon from the piston top surface.

2. Using a gasket scraper, remove all the gasket material from the cylinder block surface.

3. Using compressed air, blow carbon and oil from the bolt holes.

   CAUTION:

   Protect your eyes when using compressed air.

1. Inspect for warpage.
   

   1. Using a precision straight edge and feeler gauge, measure the warpage of the contact surfaces of the cylinder head and crankshaft bearing cap.

      Maximum warpage:

      0.07 mm (0.0028 in.)
      

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

2. Visually check the cylinder for vertical scratches.
   If deep scratches are present, rebore all the 8 cylinders and replace all the 8 pistons. If necessary, replace the cylinder block.

1. Clean the cylinder head.
   

   1. Using a gasket scraper, remove all the gasket material from the cylinder block contact surface.

      NOTICE:

      Be careful not to scratch the cylinder block contact surface.

   3. Using a wire brush, remove all the carbon from the combustion chambers.

      NOTICE:

      Be careful not to scratch the cylinder block contact surface.

   5. Using a valve guide bushing brush and solvent, clean all the guide bushes.

   7. Using a soft brush and solvent, thoroughly clean the cylinder head.

1. Inspect for warpage.
   

   1. Using a precision straight edge and feeler gauge, measure the warpage of the contact surfaces of the cylinder block and the manifolds.

      Maximum warpage:

      0.10 mm (0.0039 in.)
      

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

2. Inspect for cracks.
   

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

1. Using vernier calipers, measure the thread outside diameter of the bolt.

   Standard outside diameter:

   9.810 to 9.960 mm (0.3862 to 0.3921 in.)
   

   Minimum outside diameter:

   9.700 mm (0.3819 in.)
   

   If the diameter is less than the minimum, replace the bolt.