Intake Manifold Replacement - Lower

REMOVAL PROCEDURE





1. Disconnect both the battery negative cables from the batteries. Refer to Battery Cable in Powertrain Management.
2. Remove the upper intake manifold from the lower intake manifold. Refer to Intake Manifold Replacement (Upper).
3. Remove the fuel filter from the lower intake manifold and position to the side.
4. Remove the Glow Plug Relay from the lower intake manifold. Refer to Glow Plug Relay Replacement in Powertrain Managements.





5. Remove the EGR/Boost solenoids (L56 only) with the bracket from the intake manifold studs.
6. Remove the heater hose and bracket from the cylinder head. Refer to Heater Hoses Replacement in Heating and Air Conditioning.





7. Remove the heater hose and bracket from the cylinder head (if vehicle is equipped with rear heat). Refer to Heater Hoses Replacement - Auxiliary (Suburban-Front) in Heating and Air Conditioning.





8. Remove the ground straps from the right rear corner of the lower intake manifold.





9. Disconnect the engine wiring harness (if needed)and secure out of the way.





10. Remove the lower intake manifold bolts from the cylinder head.
11. Remove the lower intake manifold and the gasket from the cylinder heads.
12. Clean and check the sealing surfaces of the cylinder head and the engine block.

INSTALLATION PROCEDURE

Important: Be sure to use the correct gasket. The gasket for the L56 models have openings for the EGR Valve, the gaskets for the L65 models do not have openings.





1. Install the lower intake manifold gasket to the cylinder head.
2. Install the lower intake manifold to the cylinder head.





IMPORTANT: There are four stud/bolts, numbers 9, 11, 13, and 15 exposed to the crankcase, and should be sealed with Teflon sealer. Apply thread locker GM P/N 12345493 to the threads of bolts and studs numbers 1 through 8 and 10, 12, 14, and 16.

NOTICE: Refer to Fastener Notice in Service Precautions.

3. Install the lower intake manifold bolts to the cylinder head.
^ Tighten the bolts to 42 Nm (31 lb ft).





4. Install the EGR/Boost solenoids (L56 only) with the bracket to the intake manifold studs.
5. Install the Glow Plug Relay to the lower intake manifold. Refer to Glow Plug Relay Replacement in Powertrain Managements.





6. Install the grounds straps to the right rear of the cylinder head.





7. Install the engine wiring harness (right side).





8. Install the heater hose and bracket to the cylinder head (if the vehicle is equipped with rear heat). Refer to Heater Hoses Replacement - Auxiliary (Suburban-Front) in Heating and Air Conditioning.





9. Install the fuel filter to the lower intake manifold.
10. Install the upper intake manifold (L56 shown) to the lower intake. Refer to Intake Manifold Replacement (Upper).
11. Connect both the battery negative cables to the batteries. Refer to Battery Cable in Powertrain Management.