Disassembly, Inspection and Assembly

Note: For additional information on camshaft removal refer to camshaft, engine, service and repair: Service and Repair

Disassembly Procedure
1. Remove the cylinder head with the intake manifold and the exhaust manifold attached. Refer to Cylinder Head Assembly; Service and Repair Cylinder Head and Gasket.
2. Remove the coolant temperature sensor.
3. Remove the camshaft position sensor.
4. Remove the exhaust manifold heat shield bolts.
5. Remove the exhaust manifold heat shield.





6. Remove the exhaust manifold retaining nuts in the sequence shown.
7. Remove the exhaust manifold.
8. Remove the exhaust manifold gasket.
9. Remove the exhaust manifold studs.





10. Remove the thermostat housing mounting bolts.
11. Remove the thermostat housing assembly.
12. Remove the fuel rail assembly. Refer to Powertrain Management.
13. Remove the coolant bypass housing mounting bolts and the housing.





14. Remove the intake manifold retaining nuts and retaining bolt in the sequence shown.
15. Remove the intake manifold.
16. Remove the intake manifold gasket.
17. Remove the electronic ignition system (EI System) ignition coil and EGR mounting bracket bolts.
18. Remove the EI system ignition coil and EGR mounting bracket and ignition wires.
19. Remove the intake manifold studs.
20. Remove the spark plugs.





21. Remove the camshaft bearing Gap bolts gradually and in the sequence shown for each camshaft cap.
22. Remove the intake camshaft caps. Maintain the correct positions for installation.
23. Remove the intake camshaft.





24. Remove the intake valve lash adjusters.
25. Remove the exhaust camshaft caps. Maintain the correct positions for installation.
26. Remove the exhaust camshaft.
27. Remove the exhaust valve lash adjusters.





28. Compress the valve springs with the valve spring compressor KM-348 and the adapter KM-653.
29. Remove the valve retainers.
30. Remove the valve spring compressor KM-348 and the adapter KM-653.
31. Remove the valve spring caps.
32. Remove the valve springs. Maintain the original position of the valve springs for installation.
33. Remove the valves. Maintain the original position of the valves for installation.





34. Remove the valve stem seals.

Cylinder Head Inspection
1. Clean the sealing surfaces.
2. Inspect the cylinder head gasket and mating surfaces for leaks, corrosion and blow-by.
3. Inspect the cylinder head for cracks.





4. Inspect the length and width of the cylinder head using a feeler gauge and a straight edge.
5. Check the sealing surfaces for deformation and warpage. The cylinder head sealing surfaces must be flat within 0.025 mm (0.001 inch) maximum.





6. Measure the height of the cylinder head from sealing surface to sealing surface. The cylinder head height should be 133.975 to 134.025 mm (5.274 to 5.276 inches). If the cylinder head height is less than 133.9 mm (5.271 inches), replace the cylinder head.
7. Inspect all threaded holes for damage.
8. Inspect valve seats for excessive wear and burned spots.

Valve Inspection





1. Inspect the valve stem tip for wear.
2. Inspect the valve retainer grooves and the oil seal grooves for chips and wear.
3. Inspect the valves for burns or cracks.
4. Inspect the valve stem for burrs and scratches.
5. Inspect the valve stem. The valve stem must be straight.
6. Inspect the valve face for grooving. If the groove is so deep that refacing the valve would result in a sharp edge, replace the valve.
7. Inspect the valve spring. If the valve spring ends are not parallel, replace the valve spring.
8. Inspect the valve spring seating surface of the valve rotators for wear or gouges. Replace as required.

Cleaning Procedure





1. Clean the cylinder head.
2. Clean the valve guides.
3. Clean all of the threaded holes.
4. Clean the valves of carbon, oil and varnish.

Cylinder Head Overhaul
Valve Grind-in
1. Lubricate the valve seat using a fine-grained paste.





2. Lift the valve rhythmically from the seat with a commercially-available valve grinding tool in order to distribute the paste.





3. Check the contact pattern on the valve head and in the cylinder head.
4. Clean the valves, the valve guides, and the cylinder head.

Valve Grind





1. Ensure that there are no crater line burns on the valve cone.
2. The valve may be reground only two times. Do not grind the valve stem end.
3. Ensure that the angle at the valve face is 45 degrees.
4. Inspect the assembly height of the intake valves and the exhaust valves.

Valve Guide - Ream





1. Measure the diameter of the valve guide using gauge MKM-571-B and a commercially-available inside micrometer.

Important: Valve oversizes may already have been fitted in production.





2. An oversize service code is on the valve guide and the valve stem end. The following table gives the correct size, reamer, and production code for each service.





3. Ream the valve guide from the upper side of the cylinder head to the next oversize.
4. After reaming, cross out the code and emboss the valve guide with the new code.

Valve Seat - Cut
1. Place the cylinder head on wooden blocks.





2. Cut the intake and the exhaust valve seats using the guide drift KM-340-7 as follows:
- Valve seat - A 45-degree surface using the cutter KM-340-13.
- Upper correction angle - A 30-degree surface using the cutter KM-340-13.
- Lower correction angle - A 60-degree surface using the cutter KM-340-26.
3. Clean the chippings from the cylinder head.
4. Inspect the dimension for the valve seat width.
- Intake: 1.2 to 1.4 mm (0.047 to 0.055 inch).
- Exhaust: 1.4 to 1.8 mm (0.055 to 0.070 inch).
5. Inspect the assembly height of the intake valves and the exhaust valves. If the dimension is exceeded, install new valves. Inspect the assembly height of the intake valves and the exhaust valves again. If the valve assembly height is still too large despite replacing the valves, replace the cylinder head.

Assembly Procedure
1. Coat the valve stems with engine oil.
2. Insert the valves in the cylinder head in their original positions.
3. Insert the valve spring seats.
4. Push the accompanying assembly sleeve onto the valve stem.
5. Insert the new valve stem seat.





6. Carefully drive the valve stem seal onto the stop with light taps.
7. Install the valve springs in their original positions.
8. Install the valve spring caps.





9. Compress the valve springs with the valve spring compressor KM-348 and adapter KM-653.
10. Install the valve retainers.
11. Remove the valve spring compressor KM-348 and adapter KM-653.
12. Lubricate the valve lash adjusters with engine oil.





13. Install the valve lash adjusters.
14. Install the intake camshaft.
15. Install the intake camshaft bearing caps in their original positions.
16. Install the exhaust camshaft.
17. Install the exhaust camshaft bearing caps in their original positions.
18. Install the camshaft bearing cap bolts.





19. Tighten the camshaft bearing cap bolts gradually and in the sequence shown for each camshaft cap.
Tighten the camshaft bearing cap bolts to 8 Nm (71 inch lbs.).
20. Install the spark plugs.
Tighten the spark plugs to 20 Nm (15 ft. lbs.).
21. Install the EI system ignition coil and EGR mounting bracket.





22. Install the EI system ignition coil and EGR mounting bracket bolts.
Tighten the El system ignition coil and EGR mounting bracket bolts to 25 Nm (118 ft. lbs.).
23. Install the intake manifold studs.
24. Install the intake manifold gasket.
25. Install the intake manifold.





26. Install the intake manifold retaining nuts and retaining bolt in the sequence shown.
Tighten the intake manifold retaining nuts and retaining bolt to 22 Nm (116 ft. lbs.).
27. Install the fuel rail assembly. Refer to Powertrain Management.
28. Install the thermostat housing assembly.





29. Install the thermostat housing mounting bolts.
Tighten the thermostat housing mounting bolts to 15 Nm (11 ft. lbs.).
30. Install the coolant bypass housing and mounting bolts.
Tighten the coolant bypass housing and mounting bolts to 15 Nm (11 ft. lbs.).
31. Install the camshaft position sensor.
Tighten the camshaft position sensor bolts to 12 Nm (106 inch lbs.).
32. Install the exhaust manifold studs.
33. Install the exhaust manifold gasket.
34. Install the exhaust manifold.





35. Install the exhaust manifold retaining nuts in the sequence shown.
Tighten the exhaust manifold retaining nuts to 15 Nm (11 ft. lbs.).
36. Install the exhaust manifold heat shield.
37. Install the exhaust manifold heat shield bolts.
Tighten the exhaust manifold heat shield bolts to 8 Nm (71 inch lbs.).
38. Install the cylinder head with the intake manifold and the exhaust manifold attached. Refer to Cylinder Head Assembly; Service and Repair; Cylinder Head and Gasket.