Cylinder Head Assembly: Service and Repair

Remove or Disconnect

Tools Required:
J 28467-A Universal Support Fixture
J 8062 Valve Spring Compressor
J 37979-A Adapter

1. Battery negative (-) cable.
2. Drain coolant.
^ Raise and suitably support the vehicle.
3. Right lower stone shield.
4. Two mount nut and stud protectors.
5. Two rear transaxle mount-to-main crossmember mount nuts.
6. Two center mount-to-center crossmember nuts.
^ Lower vehicle.
7. Air cleaner assembly.
8. Throttle cable.
9. Cruise control actuator cable.
10. Transaxle kick-down cable.
11. All necessary electrical connections and vacuum lines.
12. Fuel inlet line.
13. Cold start injector pipe.
14. Fuel rail.
15. Coolant hoses.
16. Heater hoses.
17. Water outlet housing.
18. Water inlet housing.
19. Spark plug wires.
20. PCV valve.
21. Cylinder head cover.
^ Loosen the air conditioning compressor, power steering pump, and generator brackets as applicable.
22. Accessory drive belts.
23. Air conditioning idler pulley.
24. Electrical connections at cruise control actuator.
25. Cruise control actuator and bracket.
26. Windshield washer reservoir.
^ Support the engine with a J 28467-A support fixture.
27. Right engine mount through bolt.
^ Raise the engine.
28. Water pump pulley.
^ Lower the engine.
29. Engine wiring harness from upper timing belt cover.
^ Raise and suitably support the vehicle.
30. Cylinder head-to-cylinder block bracket.
31. Exhaust manifold support bracket.
32. Exhaust pipe from exhaust manifold.
33. Upper timing belt cover.
34. Center timing belt cover.
35. Right engine mount bracket.
36. Distributor.
^ Set the number 1 cylinder at TDC on its compression stroke. Turn the crankshaft pulley and align its groove with the "O" mark of the timing belt cover.

Aligning Camshaft Gear Hole & Exhaust Camshaft Cap Mark:

^ Check that the camshaft gear hole is aligned with the exhaust camshaft cap mark.
37. Plug from the lower timing belt cover.
^ Place alignment marks on the camshaft timing gear and belt.

Moving Idler Pulley To The Left:

^ Loosen the idler pulley mount bolt and push the idler pulley toward the left as far as it will go, then tighten it temporarily.

Marking Timing Belt & Camshaft Timing Gear:

38. Timing belt from the camshaft timing gear after marking its position in relation to the camshaft timing gear.

Holding Timing Belt With Cloth:

^ Hold the timing belt with a cloth.

Important
^ Support the belt so the meshing of the crankshaft timing gear and timing belt does not shift. Be careful not to drop anything inside the timing belt cover. Do not allow the belt to come in contact with oil, water, or dust.

Cylinder Head Bolt Removal Sequence:

39. Cylinder head bolts in the proper sequence using a 10 mm, 12 point deep well socket.

NOTICE: Head warping or cracking could result from incorrect removal.

Removing Cylinder Head From Cylinder Block:

40. Cylinder head with intake and exhaust manifolds. If the head is difficult to lift off, carefully pry with a bar between the cylinder head and a cylinder block projection.

Important
^ Be careful not to damage the cylinder head and block mating surface.
^ Lift the cylinder head from the dowels on the cylinder block and place it on wooden blocks on a bench.

41. Remove the intake and exhaust manifolds.
42. Camshafts.
43. Valve lifters and shims.
44. Spark plug tubes.
45. Engine hangers.
46. Valves using a J 8062 spring compressor and a J 37979-A adapter.
47. Valve stem oil seals.

Half Circle Plug:

48. Half circle plug.

Clean
^ Cylinder head using a soft brush and solvent.

Inspect
1. Cylinder head mating surfaces with a feeler gage and a precision straightedge. If warpage exceeds 0.05 mm (0.0020-inch) on the cylinder block side or 0.10 mm (0.0039-inch) on either manifold side, replace the cylinder head.
2. Cylinder head for cracks using a dye penetrant. Check the combustion chamber, intake and exhaust ports, head surface and the top of the head for cracks. If any cracks are found, replace the cylinder head.
^ Clean the valves thoroughly using a wire brush.
3. Valve stems and valve guide bushings.
^ Measure the inside diameter of the valve guide bushings with a hole gage.
^ Measure the diameter of the valve stems with a micrometer. If any intake valve stem diameter is not 5.979 to 5.985 mm (0.2350 to 0.2356-inch), replace the valve. If any exhaust valve stem diameter is not 5.965 to 5.980 mm (0.2348 to 0.2354-inch), replace the valve.
^ Subtract the valve stem diameter measurement from the valve guide bushing measurement. The difference between the two measurements is the oil clearance. Oil clearance must not exceed 0.08 mm (0.0031-inch) for intake valves or 0.10 mm (0.0039-inch) for exhaust valves. If the oil clearance on any valve exceeds this specification, replace the valve guide bushing.

Remove or Disconnect

Tools Required:
J 37133 Valve Guide Bushing Remover/Installer
J 37972 Reamer

^ Gradually heat the cylinder head to 80° to 100°C (176° to 212°F).
1. Valve guide bushing using a J 37133 remover/installer and a hammer.

Measure
Tool Required:
J 37972 Reamer

^ Cylinder head bushing bore diameter with a hole gage. If the bushing bore diameter is greater than 11.077 mm (0.4361-inch), replace the cylinder head. If the bushing bore diameter is greater than 11.027 mm (0.4341-inch), machine the bore to 11.050 to 11.077 mm (0.4350 to 0.4361-inch) using a J 37972 reamer.

Install or Connect

Tools Required:
J 37133 Valve Guide Bushing Remover/Installer
J 38277 Adapter
J 38342 Reamer

^ Gradually heat the cylinder head to 80° to 100°C (176° to 212°F).
1. Oversized valve guide bushing using a J 37133 remover/installer, a J 38277 adapter, and a hammer. Install the valve guide bushing to an extrusion height of 12.7 to 13.1�mm (0.500 to 0.516-inch).
2. Ream the valve guide bushing with a J 38342 reamer to obtain the proper oil clearance between the valve and the new valve guide bushing. Oil clearance for intake valves should be 0.025 to 0.060 mm (0.0010 to 0.0024-inch). Oil clearance for exhaust valves should be 0.030 to 0.065 mm (0.0012 to 0.0026-inch).
3. Grind the valves so that the carbon and pitting are removed.
4. Valve face angle. If valve face angle is not 45.5°, the valve face must either be reground to meet this specification or the valve must be replaced.
5. Valve head margin thickness. If the valve head margin thickness is less than 0.5 mm (0.020-inch), replace the valve.
6. Overall length of the valve. Replace any intake valve that does not have an overall length of at least 90.95 mm (3.5807-inch). Replace any exhaust valve that does not have an overall length of at least 91.40 mm (3.5984-inch).
7. Valve stem tip surface for wear. If the valve stem tip is worn, resurface the tip with a grinder or replace the valve.

Important
^ When grinding any valve tip, be sure not to grind the tip past the point where the valve no longer meets the minimum overall length requirements.

Clean
^ Valve seats with a 45° carbide cutter. Remove only enough metal to clean the seats.

8. Valve seating position by applying a thin coat of prussian blue to the valve face and installing the valve. Rotate the valve against the seat while applying slight pressure.
^ If blue appears 360° around the face of the valve, the valve is concentric. If not, replace the valve.
^ If blue appears 360° around the valve seat, the guide and seat are concentric. If not, resurface the seat.
9. Valve face to seat contact. Check that the seat contact is on the middle of the valve face with a 1.0 to 1.4 mm (0.039 to 0.055-inch) width.
^ If the seating is too high on the valve face, use 30° and 45° cutters to correct the seat.
^ If the seating is too low on the valve face, use 60° and 45° cutters to correct the seat.
^ Hand lap the valve and valve seat with an abrasive compound.
^ Clean the valve and valve seat after hand lapping.
10. Squareness of the valve spring with a steel square. If there is more than a 2.5 mm (0.098-inch) variance in the squareness, replace the valve spring.
11. Valve spring free length. If free length is less than 43 mm (1.724-inch), replace the valve spring.
12. Valve spring tension with a spring tester. If spring tension is less than 143 N.m (32.2 lb.), replace the valve spring.

Install or Connect

Tools Required:
J 38232 Valve Guide Seal Installer
J 8062 Valve Spring Compressor
J 37979-A Adapter
J 28467-A Universal Support Fixture

Half Circle Plug With Sealant Applied:

1. Half circle plug to cylinder head. Apply GM # 1052751 sealant to the plug.
2. Valves.
3. New oil seals on the valves using a J 38232 seal installer.

Important
^ The intake valve oil seal is brown and the exhaust valve oil seal is black.

4. Spring seat, spring, and spring retainer on the cylinder head. Using a J 8062 spring compressor and a J 37979-A adapter, compress the valve springs and place the 2 keepers around valve stem. Remove the J 8062 spring compressor and the J 37979-A adapter.
^ Apply GM # 1052751 sealant to the spark plug tube hole of the cylinder head, and using a press, install a new spark plug tube to a protrusion height of 46.6 to 47.4 mm (1.835 to 1.866-inch).
5. Engine hangers to the cylinder head.
6. Valve lifters and shims.
7. Camshafts.
8. Intake manifold.
9. Exhaust manifold.

Cylinder Head Gasket Aligned On Cylinder Block:

10. New cylinder head gasket to cylinder block.
^ Carefully install the cylinder head in position on the cylinder head gasket.

Important
^ Apply a light coating of engine oil on the bolt threads and under the bolt head before installation.

Cylinder Head Bolt Tightening Sequence:

11. Ten cylinder bead bolts in several passes and in the proper sequence.

Tighten
^ Cylinder head bolts to 60 N.m (44 lb.ft.).

12. Timing belt.
13. Distributor.
14. Engine mount bracket.
15. Air conditioning idler pulley.
16. Center timing belt cover.
17. Upper timing belt cover.
^ Raise and suitably support the vehicle.
18. Exhaust manifold to exhaust pipe with a new gasket.
19. Two new exhaust pipe bolts.

Tighten
^ Exhaust pipe bolts to 25 N.m (18 lb.ft.).

20. Exhaust manifold support bracket.
21. Cylinder head-to-cylinder block bracket.
^ Lower vehicle.
22. Engine harness to upper timing belt cover.
^ Raise the engine.
23. Water pump pulley.
^ Lower engine.
24. Right engine mount through bolt.

Tighten
^ Right engine mount through bolt to 87 N.m (64 lb.ft.).

^ Remove the J 28467-A support fixture.
25. Windshield washer reservoir.
26. Cruise control actuator and bracket.
27. Electrical connections at the cruise control actuator.
28. Accessory drive belts and adjust to the proper tensions as applicable.
29. Cylinder head cover.
30. PCV valve.
31. Spark plug wires.
32. Water inlet housing.
33. Water outlet housing.
34. Heater hoses.
36. Fuel rail.
37. Cold-start injector pipe.
38. Fuel inlet line.
39. All necessary electrical connections and vacuum lines.
40. Transaxle kick-down cable.
41. Cruise control actuator cable.
42. Throttle cable.
43. Air cleaner assembly.
^ Raise and suitably support the vehicle.
44. Two rear mount-to-main crossmember nuts.
45. Two center transaxle mount-to-center crossmember nuts.

Tighten
^ Rear transaxle mount-to-main crossmember nuts to 61 N.m (45 lb.ft.).
^ Center transaxle mount-to-center crossmember nuts to 61 N.m (45 lb.ft.).

46. Both mount nut and stud protectors.
47. Right lower stone shield.
^ Lower vehicle.
^ Refill coolant.
48. Battery negative (-) cable.