1. Disconnect the battery negative cables from the batteries. Refer to Battery Cable in Engine Electrical.
2. Remove the CDR valve from the valve rocker arm cover.
3. Remove the upper intake manifold from the lower intake manifold. Refer to Intake Manifold Replacement .



4. Remove the wiring harness from the right side of the engine assembly.



5. Remove the wiring harness from the left side of the engine assembly.
6. Remove the lower intake manifold from the engine assembly. Refer to Intake Manifold Replacement .
7. Remove the turbocharger if replacing the right valve rocker arm cover. Refer to Turbocharger .
8. Remove the oil level indicator and tube if replacing the left valve rocker arm cover. Refer to Oil Level Indicator and Tube Replacement .
9. Remove the heater hoses from engine assembly. Refer to Heater Hoses Replacement and Heater Hoses Replacement - Auxiliary in HVAC.
10. Remove the fuel injection lines from the fuel injectors. Refer to Injection Line(s) Replacement in Engine Controls-6.5L.



11. Remove the valve rocker arm cover bolts from the cylinder head.




Notice: Prying on the valve rocker arm cover may cause damage to the sealing surfaces. Use a block of wood against the side of the valve rocker arm cover and strike with a hammer in a sideways direction to shear the RTV sealant.

12. Remove the valve rocker arm cover from the cylinder head.
13. Remove all oil and grease from the sealing surfaces.

Notice: Do not allow the RTV sealant to enter any blind threaded hole. RTV sealant that is allowed to enter a blind threaded hole can cause hydraulic lock of the fastener when the fastener is tightened. Hydraulic lock of a fastener can lead to damage to the fastener and/or the components. Hydraulic lock of a fastener can also prevent the proper clamping loads to be obtained when the fastener is tightened. Improper clamping loads can prevent proper sealing of the components allowing leakage to occur. Preventing proper fastener tightening can allow the components to loosen or separate leading to extensive engine damage.

1. Apply a 5 mm (3/16 inch) bead of RTV sealant GM P/N 12345739 to the valve rocker arm cover, inboard of the bolt holes. The sealer must be wet to the touch when the bolts are tighten.



2. Install the valve rocker arm cover to the cylinder head.




Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

3. Install the valve rocker arm cover bolts to the cylinder head.

Tighten
Tighten the bolts to 22 N·m (16 lb ft).

4. Install the fuel injection lines to the fuel injection pump and fuel injectors. Refer to Injection Line(s) Replacement in Engine Controls--6.5L .
5. Remove the lower intake manifold from the engine assembly. Refer to Intake Manifold Replacement .
6. Install the upper intake manifold to the lower intake manifold. Refer to Intake Manifold Replacement .



7. Install the wiring harness to the right side of the engine assembly.



8. Install the wiring harness to the left side of the engine assembly.



9. Install the CDR valve to the valve rocker arm cover.
10. Install the heater hoses on the engine assembly. Refer to Heater Hoses Replacement and Heater Hoses Replacement - Auxiliary in HVAC.
11. Install the oil level indicator and tube on the engine assembly if removed. Refer to Oil Level Indicator and Tube Replacement .
12. Install the turbocharger on the exhaust manifold if removed. Refer to Turbocharger .
13. Connect the battery negative cables to the batteries. Refer to Battery Cable in Engine Electrical.