Hummer H1 (2006+). Manual - part 34

2-42

Engine

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Figure 2-38:   Right Side Cylinder Head Removal/Installation

Cylinder Head (Right Side) (Figure  2-38)

Installation 

NOTE: þThe left and right cylinder head gaskets are not interchangeable. Improper placement of the cylinder head gasket will
block coolant and oil passages. Blocked coolant and oil passages will cause severe engine damage.

1.

Install the cylinder head gasket of the correct grade (Figure  2-37).

2.

Install the cylinder head.

NOTE: þThis component uses bolts with a preapplied molybdenum disulfide coating for thread lubrication. Do not remove the
coating or use any additional lubricant. Improperly lubricated threads will adversely affect the bolt torque and clamp load. Im-
proper bolt torque and clamp load can lead to engine damage.

3.

Install NEW M12 cylinder head bolts. 

4.

Reuse the M8 cylinder head bolts.

5.

Torque the cylinder head bolts in the following steps using the sequence shown (Figure  2-35).

a.

Tighten the M12 bolts a first pass to 50þN·m (37þlbþft).

b.

Tighten the M12 bolts a second pass to 80þN·m (59þlbþft)

c.

Tighten the M12 bolts a third pass to 90þdegrees, using J 45059.

d.

Tighten the M12 bolts a final pass to 75þdegrees, using J 45059.

e.

Tighten the M8 bolts to 25þN·m (18þlbþft).

6.

Install the valve rocker arm shaft, pushrods and valve bridges and adjust the valves.

7.

Install the glow plugs.

8.

Install the exhaust manifold

9.

Install the intake manifold.

10. Install the thermostat housing crossover.

11. Fill and bleed the cooling system.

12. Connect the negative battery cable.

13. Road test the vehicle for normal operation.

Inspect for coolant, oil or exhaust leaks.

GASKET

CYLINDER HEAD

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 Engine  2-43

5745804

INTAKE MANIFOLD

Service

A three-piece intake manifold and two piece intake pipe is used on the turbocharged diesel engines (Figure  2-39). It consists of left
and right manifold halves and a center manifold. The center manifold joins the other manifold halves to the lower inlet pipe which
connects to the charged air cooler and the upper inlet pipe, that connects to the EGR pipe.

Center Intake Manifold 

Removal

1.

Remove the exhaust gas recirculation (EGR) valve cooler tube (Refer to section 3).

2.

Remove the intake manifold tube.

3.

Remove and discard the 2þintake manifold tube O-ring gaskets.

4.

Remove the turbocharger  (See “Turbocharger Service and Diagnosis” on page 2-15) .

5.

Remove the center intake manifold bolts and nuts.

6.

Pull-up the center intake manifold in order to remove.

7.

Remove and discard the gaskets.

8.

Clean the center intake manifold in cleaning solvent and air dry.

Installation

1.

Install the center intake manifold with NEW gaskets torque the nuts and bolts to 89þlb-in. (10þN·m).

2.

Install the turbocharger.

3.

Install two NEW O-rings onto the intake manifold tube.

4.

Lubricate the O-rings with clean engine oil to aid in the installation and install the intake manifold tube.

5.

Install the EGR valve cooler tube.

6.

Test drive and check for proper operation.

Left Intake Manifold

Removal

1.

Remove the center intake manifold  (See “Intake Manifold” on page 2-43) .

2.

Remove the left fuel rail (Refer to section 3).

3.

Remove the intake manifold nuts and bolts.

NOTE: The intake manifold uses sealer. Pry at the area by the fuel rail bolt holes in order to avoid damage to the sealing surface.

4.

Remove the intake manifold.

5.

Clean the intake manifold in cleaning solvent and air dry.

Installation

1.

Apply a 2-3þmm (1/8þin) wide, by 0.5-1.5þmm (1/16þin) high bead of sealant, GMþP/Nþ97720043 or equivalent to the intake 
manifold sealing surface.

2.

Install the intake manifold, torque the intake manifold nuts and bolts in the sequence shown (Figure  2-40) to 15þlb-ft.
(21þN·m).

3.

Install the left fuel rail.

4.

Install the center intake manifold.

5.

Test drive and check for proper operation.

2-44

Engine

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Figure 2-39:   Intake Manifold Attachment 

CENTER MANIFOLD

GASKET

GASKET

LEFT INTAKE 

RIGHT INTAKE 

MANIFOLD

MANIFOLD

GASKET

UPPER INTAKE

PIPE

LOWER INTAKE 

PIPE

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 Engine  2-45

5745804

Figure 2-40:   Left Intake Manifold Torque Sequence

Right Intake Manifold

Removal

1.

Remove the center intake manifold (Refer to section 2).

2.

Remove the right fuel rail (Refer to section 3).

3.

Remove the intake manifold nuts and bolts.

NOTE: The intake manifold uses sealer. Pry at the area by the fuel rail bolt holes in order to avoid damage to the sealing surface.

4.

Remove the intake manifold.

5.

Clean the intake manifold in cleaning solvent and air dry.

Installation

1.

Apply a 2-3þmm (1/8þin) wide, by 0.5-1.5þmm (1/16þin) high bead of sealant, GMþP/Nþ97720043 or equivalent to the intake 
manifold sealing surface.

2.

Install the intake manifold, torque the intake manifold nuts and bolts in the sequence shown to 15þlb-ft. (21þN·m) (Figure

2-41).

3.

Install the right fuel rail.

4.

Install the center intake manifold.

5.

Test drive and check for proper operation.

Figure 2-41:   Right Intake Manifold Torque Sequence

8

4

1

5

9

10

6

2

3

7

11

9

5

1

4

8

10

6

2

3

7

11