Intake Manifold Replacement Upper

1. Disconnect the battery negative cables from the batteries. Refer to Battery Cable Replacement in Engine Electrical.
2. Remove the air cleaner assembly and the mounting brackets from the engine assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls-6.5L-L65.
3. Disconnect the engine electrical harness.
4. Remove the bolt for the upper intake manifold.
5. Remove the upper intake manifold.
6. Remove the O-ring between the upper intake manifold and the turbocharger.

Discard the O-ring.

1. Lightly lubricate a new O-ring with clean engine oil.
2. Install the O-ring between the upper intake manifold and the turbocharger.

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 bolt for the upper intake manifold.

Tighten
Tighten the upper intake manifold bolt to 23 N·m (17 lb ft).

4. Connect the engine electrical harness.
5. Install the air cleaner assembly and the mounting brackets to the engine assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls-6.5L-L65.
6. Connect the battery negative cables from the batteries. Refer to Battery Cable Replacement in Engine Electrical.

Intake Manifold Replacement Lower

Important: Do not attempt to remove the upper and lower intake manifolds as an assembly. Difficulty in re alignment of the upper and lower intake manifolds to the turbocharger will occur during the installation.

1. Disconnect the battery negative cables from the batteries. Refer to Battery Cable Replacement in Engine Electrical.
2. Remove the air cleaner assembly with the mounting brackets from the engine assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls-6.5L-L65.
3. Remove the crankcase depression regulator (CDR) valve (right side).
4. Remove the boost sensor from the lower intake manifold. Refer to Boost Sensor Replacement in Engine Controls-6.5L-L65.
5. Remove the upper intake manifold. Refer to Intake Manifold Replacement .
6. Disconnect the electrical harness.
7. Remove the glow plug relay from the lower intake manifold. Refer to Glow Plug Relay Replacement in Engine Controls-6.5L-L65.



8. Remove the vacuum solenoids from the lower intake manifold.
9. The vacuum lines



10. Remove the stud/nuts from the intake manifold.
11. Remove the intake manifold.
12. Remove the intake manifold gasket.
13. Clean the gasket surfaces on the cylinder heads.

1. Install the intake manifold gasket.
2. Install the intake manifold.
3. Replace the O-ring between the upper intake manifold and the turbocharger. Slightly lubricate the new O-ring with clean engine oil.
4. Apply teflon sealer GM P/N 1236004 onto the threads of the stud/nuts that are second from the ends of the intake manifold.
5. Apply threadlocker GM P/N 12345493 onto the remaining stud/nuts.

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.

6. Install the intake manifold stud/nuts.

Tighten
Tighten the stud/nuts to 42 N·m (31 lb ft).

7. Install the glow plug relay to thew lower intake manifold. Refer to Glow Plug Relay Replacement in Engine Controls-6.5L-L65.
8. Connect the electrical harness.
9. Install the upper intake manifold. Refer to Intake Manifold Replacement .
10. Install the boost sensor to the lower intake manifold. Refer to Boost Sensor Replacement in Engine Controls-6.5L-L65.



11. Install the vacuum solenoids to the lower intake manifold.
12. Install the vacuum lines to the engine assembly.
13. Connect the engine wiring harness.



14. Install the crankcase depression regulator (CDR) valve (right side).
15. Install the air cleaner assembly with the mounting brackets to the engine assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls-6.5L-L65.
16. Connect the battery negative cables to the batteries. Refer to Battery Cable Replacement in Engine Electrical.