Cylinder Head Replacement - Left Side 6.2L, LS3, 7.0L, LS7

Special Tools

1. Remove the valve rocker arms and pushrods. Refer to Valve Rocker Arm and Push Rod Replacement.
2. Remove the engine coolant air bleed pipe and covers. Refer to Coolant Air Bleed Pipe Assembly Replacement.
3. Remove the generator bracket. Refer to Generator Bracket Replacement.
4. Remove the exhaust manifold. Refer to Exhaust Manifold Replacement - Left Side.
5. Remove the intake manifold. Refer to Intake Manifold Replacement.
6. Remove the engine wiring harness ground bolt from the rear of the left cylinder head.
7. Reposition the engine wire harness ground strap away from the cylinder head.




Note: The cylinder head bolts are NOT reusable.

8. Remove the cylinder head bolts.

Caution: After removal, place the cylinder head on 2 wood blocks in order to prevent damage to the sealing surfaces.

9. Remove the cylinder head.



10. Remove the cylinder head gasket (217).
11. Discard the gasket.
12. Discard all M8 and M11 cylinder head bolts.
13. Clean and inspect the cylinder head. Refer to Cylinder Head Cleaning and Inspection.

Warning: Refer to Safety Glasses Warning in the Preface section.





Caution: Clean all dirt, debris, and coolant from the engine block cylinder head bolt holes. Failure to remove all foreign material may result in damaged threads, improperly tightened fasteners or damage to components.

Note: 

•	Do not use the cylinder head bolts again. Install NEW cylinder head bolts during assembly.

•	Do not use any type of sealant on the cylinder head gasket, unless specified.

•	The cylinder head gaskets must be installed in the proper direction and position.

1. Clean the engine block cylinder head bolt holes, if required.

Thread repair tool J 42385-107 may be used to clean the threads of old threadlocking material.

2. Spray cleaner into the hole. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.
3. Clean the cylinder head bolt holes with compressed air.
4. Install the cylinder head locating pins (230).



5. Inspect the locating pins for proper installation.



6. Inspect the displacement markings on the gasket for proper usage.



7. Install the NEW cylinder head gasket (217) onto the locating pins.



8. Install the cylinder head (218) onto the locating pins and the gasket.
9. Install the NEW cylinder head bolts (200, 221).

Caution: Refer to Fastener Caution in the Preface section.




10. Tighten the cylinder head bolts.

10.1.

Tighten the M11 cylinder head bolts (1-10) a first pass in sequence to 30 N·m (22 lb ft).

10.2.

Tighten the M11 cylinder head bolts (1-10) a second pass in sequence to 90 degrees using the J 45059 .

10.3.

Tighten the M11 cylinder head bolts (1-10) a final pass in sequence to 70 degrees using the J 45059 .

10.4.

Tighten the M8 cylinder head bolts (11-15) to 30 N·m (22 lb ft). Begin with the center bolt (11) and alternating side-to-side, work outward tightening all of the bolts.

11. Install the intake manifold. Refer to Intake Manifold Replacement.



12. Position the engine wire harness ground strap against the cylinder head.
13. Install the engine wiring harness ground bolt to the rear of the left cylinder head. Tighten the bolt to 32 N·m (24 lb ft).
14. Install the exhaust manifold. Refer to Exhaust Manifold Replacement - Left Side.
15. Install the generator bracket. Refer to Generator Bracket Replacement.
16. Install the engine coolant air bleed pipe. Refer to Coolant Air Bleed Pipe Assembly Replacement.
17. Install the valve rocker arms and pushrods. Refer to Valve Rocker Arm and Push Rod Replacement.

Cylinder Head Replacement - Left Side LS9

Special Tools

1. Open the hood and remove.



2. Disconnect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection.



3. Raise the vehicle and drain the engine cooling system.



4. Drain the intercooler cooling system, at left front of the vehicle.
5. Lower the vehicle.



6. Remove the sight shield.



7. Disconnect the mass air flow (MAF) sensor electrical connector, at the air inlet duct.



8. Disconnect the positive crankcase ventilation (PCV) fresh air tube from the air inlet duct.
9. Remove the air inlet duct.



10. Disconnect the throttle actuator electrical connectors from the throttle body. Do not remove the throttle body.



11. Remove the supercharger and accessory drive belts.



12. Disconnect the intercooler cooling system hoses, two large coolant hoses at the front of the intercooler retained by quick connects.
13. Disconnect the generator electrical connector and battery positive cable.
14. Remove the generator.



15. Disconnect the purge solenoid electrical connector, at left front of the supercharger.
16. Remove the purge tube from the purge solenoid.



17. Disconnect the electrical connector from the supercharger actuator solenoid, at left front of the supercharger. Do not remove the solenoid.
18. Disconnect the active exhaust vacuum hose from the front of the supercharger assembly, the small hose that routes from the left side of the engine compartment to the front of the supercharger.
19. Disconnect the brake booster vacuum hose from the front of the supercharger assembly, the large hose that routes from the left side of the engine compartment to the front of the supercharger.



20. Disconnect the coolant temperature sensor electrical connector.
21. Remove the coolant temperature sensor from the cylinder head.
22. Disconnect the fuel injector and ignition coil harness connector.



23. Disconnect the air outlet pressure sensor harness connector from the sensor and separate the harness from the fuel rail bracket and reposition, left side of intercooler. Do not remove the sensor from the intercooler.
24. Disconnect the barometric sensor electrical connector, right side of intercooler. Do not remove the sensor from the intercooler.
25. Disconnect the inlet air temperature sensor electrical connector from the sensor, right side of intercooler. Do not remove the sensor from the intercooler.
26. Disconnect the fuel injector and ignition coil harness connector, multi-pin connector at the right rear of the engine.
27. Disconnect the engine wiring harness from the fuel rail bracket, right side, and reposition.



28. Disconnect and remove the PCV fresh air hose assembly from the right and left valve covers and dry sump oil tank.
29. Disconnect the ignition coil electrical connectors from the ignition coil.



30. Remove the rear hood seal from the cowl.
31. Raise the vehicle and remove sway bar bushing-to-cradle brackets and bolts, left and right sides.
32. Loosen the engine cradle bolts and lower the engine assembly and cradle assembly approximately 1 inch.
33. Lower the vehicle.



34. Remove the intercooler cover and bolts.
35. Place the supercharger rotor cover over the exposed areas of the rotors to avoid entry of dirt or debris.



36. Remove the PCV dirty air hose from the supercharger.
37. Bleed the fuel system to 0 psi at service test port.
38. Disconnect the fuel system to fuel feed-to-rail hose using the J-37088-A disconnect tool .



39. Remove the supercharger bolts.
40. Remove the supercharger assembly.
41. Remove the power steering pump bracket bolts, reposition the pump and bracket assembly forward away from the cylinder head. Remove the pump and bracket as an assembly. Do not separate the pump from the pulley and bracket assembly.



42. Disconnect the spark plug wires from the spark plugs.
43. Remove the rear ignition coil from the rocker cover.
44. Remove the rocker cover.



45. Loosen the valve rocker arm bolts and lift the rocker arms, pedestal, and bolts assembly from the left cylinder head. Discard the rocker arms and bolts, retain the pedestal.
46. Remove and discard the pushrods.
47. Remove the spark plugs.
48. Raise the vehicle.



49. Remove the exhaust manifold to cylinder head bolts. Reposition the exhaust manifold away from the cylinder head. Discard the bolts.
50. Remove and discard the exhaust manifold to cylinder head gasket.



51. Remove and discard the cylinder head bolts. DO NOT use an impact to remove the head bolts.
52. Remove and discard the cylinder head gasket.

Warning: Refer to Safety Glasses Warning in the Preface section.





Caution: Clean all dirt, debris, and coolant from the engine block cylinder head bolt holes. Failure to remove all foreign material may result in damaged threads, improperly tightened fasteners or damage to components.

Note: 

•	Do not use the cylinder head bolts again. Install NEW cylinder head bolts during assembly.

•	Do not use any type of sealant on the cylinder head gasket, unless specified.

•	The cylinder head gaskets must be installed in the proper direction and position.

1. Clean the engine block cylinder head bolt holes, if required.
2. Spray cleaner GM P/N 12346139 (Canadian P/N 10953463), GM P/N 12377981 (Canadian P/N 10953463), or equivalent, into the hole.
3. Clean the cylinder head bolt holes with compressed air.
4. Install the cylinder head locating pins (230).



5. Inspect the locating pins for proper installation.



6. Inspect the displacement markings on the gasket for proper usage.



7. Install the NEW cylinder head gasket (217) onto the locating pins. Install the gasket with the "FRONT" markings at front of engine.
8. Install the cylinder head (218) onto the locating pins and the gasket.
9. Lubricate the threads of the bolts with clean engine oil.
10. Install the NEW cylinder head bolts (220, 221).

Caution: Refer to Fastener Caution in the Preface section.




11. Tighten the cylinder head bolts.

11.1.

Tighten the M12 cylinder head bolts (1-10) a first pass in sequence to 20 N·m (15 lb ft).

11.2.

Tighten the M12 cylinder head bolts (1-10) a second pass in sequence to 80 N·m (60 lb ft).

11.3.

Tighten the M12 cylinder head bolts (1-10) a third pass in sequence to 90  degrees using the J-45059 meter .

11.4.

Tighten the M12 cylinder head bolts (1-10) a final pass in sequence to 45 degrees using the J-45059 meter .

11.5.

Tighten the M8 cylinder head bolts (11-15) to 30 N·m (22 lb ft). Begin with the center bolt (11) and alternating side-to-side, work outward tightening all of the bolts.