1. Remove the lower intake manifold. Refer to Lower Intake Manifold Replacement .
2. Remove the wiring harness from the left side of the engine.
3. Remove the oil level indicator from the engine assembly. Refer to Oil Level Indicator and Tube Replacement .
4. Remove the fuel injector lines from the fuel injector nozzles. Refer to Fuel Injection Line Replacement in Engine Controls - 6.5L (L65).



5. 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.

6. Remove the valve rocker arm cover from the cylinder head.
7. Remove all oil and grease from the sealing surface of the cylinder head(s).

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. Clean the sealing surfaces on the cylinder head and the valve rocker arm cover, so that the surfaces are free from oil and foreign material.




Important: The RTV should be applied such that it follows and overlaps the stepped ridge. This will distribute RTV on both the upper and lower levels of the step. When the valve rocker arm cover is fastened to the cylinder head, the RTV should flow on to both upper and lower levels of the step.

2. Apply a 5-8 mm (3/16-5/16 in) bead of RTV sealant GM P/N 12346286 to the left valve rocker arm cover, inboard of the bolt holes. The sealer must be wet to the touch, when the bolts are tightened.



3. Install the left valve rocker arm cover.

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.

4. Install the left valve rocker arm cover bolts.

Tighten
Tighten the left valve rocker arm cover bolts to 27 N·m (20 lb ft).




5. Install the fuel injection lines to the fuel injection pump and fuel injectors. Refer to Fuel Injection Line Replacement in Engine Controls - 6.5L (L65).
6. Install the lower intake manifold on the cylinder heads. Refer to Lower Intake Manifold Replacement .
7. Install the oil level indicator to the mounting bracket . Refer to Oil Level Indicator and Tube Replacement .
8. Install the wiring harness to the left side of the engine.