Cylinder Head and Gasket Surface Clean and Inspect

1. Inspect the cylinder head gasket and mating surfaces for leaks corrosion and blow-by. If the gasket has failed, use the following faults to determine the cause:
1.1. Improper installation
1.2. Loose or warped cylinder head
1.3. Missing, off location or not fully seated dowel pins
1.4. Corrosion in the seal area around the coolant passages
1.5. Chips or debris in the cylinder head bolt holes
1.6. Bolt holes in the cylinder block not drilled or tapped deep enough
1.7. Other





2. Inspect the cylinder head gasket surface.
^ Cylinder head may be reused if corrosion is found only outside a 4 mm (0.375 inch) band around each combustion chamber (1).
^ Replace the cylinder head if the area between the valve seats is cracked (2).
^ Replace the cylinder head if corrosion has been found inside a 4 mm (0.375 inch) band around each combustion chamber (3).

Important: Do not use a wire brush on any gasket sealing surface.

3. Clean the cylinder head. Remove all varnish, soot and carbon to the bare metal.
4. Clean the valve guides.
5. Clean the threaded holes. Use a nylon bristle brush.
6. Clean the remains of the sealer from the plug holes.
7. Replace all suspect bolts.
8. Inspect the cylinder head for cracks. Check between the valve seats and in the exhaust ports.

Important: Do not attempt to weld the cylinder head, replace it.

9. Inspect the cylinder head deck for corrosion, sand inclusions, and blow holes.





10. Inspect the cylinder head deck surface for flatness.
Maximum Cylinder Head Deck Warpage: 0.05 mm (0.0020 inch)
11. If the warpage is greater than the maximum allowed, replace the cylinder head.
12. Inspect all the threaded holes for damage. Threads may be reconditioned with thread inserts.
13. Inspect the sealing surfaces.





14. Inspect the cylinder head intake manifold surface for flatness.
Maximum Cylinder Head Intake Surface Warpage: 0.05 mm (0.0020 inch)
15. If the warpage is greater than the maximum allowed, replace the cylinder head.
16. Inspect all the threaded holes for damage. Threads may be reconditioned with thread inserts.
17. Inspect the sealing surfaces.





18. Inspect the cylinder head exhaust manifold surface for flatness.
Maximum cylinder head exhaust surface warpage: 0.05 mm (0.0020 inch)
19. If the warpage is greater than the maximum allowed, replace the cylinder head.
20. Inspect all the threaded holes for damage. Threads may be reconditioned with thread inserts.
21. Inspect the sealing surfaces.