62. Cylinder Head Clean and Inspect

Please refer to TSB# 06-06-01-006B for updated information


Cylinder Head Cleaning and Inspection

- Tools Required
- J 9666 Valve Spring Tester





1. Clean the cylinder head of all foreign material. Do not use a motorized wire brush on any gasket sealing surface.
2. Clean the threaded holes.
3. Inspect the cylinder head for the following:
- Damage to the gasket surfaces
- Damage to the threaded bolt holes
- Cracks in the exhaust ports
- External cracks in the water chamber
- Cracks between the valve seats
- Restrictions in the intake or exhaust passages
- Restrictions in the cooling system passages
- Rusted, damaged or leaking core plugs
4. Measure the cylinder head for warpage with a straight edge and a feeler gauge. A cylinder head block deck with warpage in excess of 0.075 mm (0.0030 inch) within a 516.5 mm (20.33 inch) area must be replaced.





5. Measure the cylinder head exhaust manifold deck for warpage. A cylinder head exhaust manifold deck with warpage in excess of 0.1 mm (0.0039 inch) within a 453 mm (17.83 inch) area must be replaced.





6. Measure the cylinder head intake manifold deck for warpage. A cylinder head intake manifold deck with warpage in excess of 0.3 mm (0.011 inch) within a 493 mm (19.41 inch) area must be replaced.





7. Measure the valve spring tension using J 9666 Replace the valve spring if the valve spring tension is less than 315.5 N (7.09 lb.) at 41 mm (1.6142 inch).





8. Measure the valve spring for squareness. Replace the valve spring if squareness is beyond 2.0 mm (0.0787 inch).





9. Measure the valve spring free length. The production free length is 56.6 mm (2.2283 inch).
10. Measure the valve stem to guide clearance.
10.1. Set a dial indicator to the valve stem measuring point.
10.2. Move the valve stem from side to side while reading the total movement on the dial indicator. If the measured valve exceeds 0.20 mm (0.0079 inch), replace the cylinder head.





11. If the valve stem to guide clearance is over 0.25 mm (0.098 inch) for the exhaust valve guides or 0.20 mm (0.0079 inch) for the intake valve guides, the cylinder head must be replaced.
12. Inspect the valves for the following:
- Bent valve stem
- Scored valve stem
- Worn valve key grooves
- Pitted surfaces





13. Measure the valve margin. The intake valve production margin is 1.2 mm (0.0472 inch) and the service limit is 0.88 mm (0.0346 inch). The exhaust valve production margin is 1.0 mm (0.0394 inch) and the service limit is 0.73 mm (0.0287 inch). Replace the valve if the valve margin is below the service limit.





14. Measure the valve depression.
14.1. Insert a new valve into the cylinder head (1).
14.2. Use a depth gauge or a straight edge to measure the valve depression from the cylinder head gasket surface (2). The intake valve depression is 0.6 mm (0.0236 inch) and the service limit is 2.5 mm (0.0984 inch). The exhaust valve depression is 0.9 mm (0.0354 inch) and the service limit is 2.0 mm (0.0787 inch). Recondition the valve seat if the valve depression is above specifications.





15. Measure the valve contact width.
- Inspect the valve contact area for roughness or unevenness.
- The intake valve contact width is 2.1 mm (0.0827 inch) and the service limit is 2.5 mm (0.0984 inch).
- The exhaust valve contact width is 2.1 mm (0.0827 inch) and the service limit is 2.5 mm (0.0984 inch).
- Recondition the valve seats to bring the contact width into specifications.