Hummer H1 (2006+). Manual - part 28

2-18

Engine

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Turbocharger Removal

1.

Remove the center console cover, the upper crash pad, and the engine cover.

2.

Disconnect the exhaust down pipe from the turbocharger exhaust housing and remove (Figure  2-7). 

3.

Remove the turbo pipe heat shields and the turbo pipes (Figure  2-8).

4.

Drain the cooling system.

5.

Remove the air cleaner outlet duct.

6.

Remove the charged air cooler outlet duct from the intake.

7.

Remove the charged air cooler inlet duct connector from the turbocharger.

8.

Remove the turbocharger inlet coolant hose from the turbocharger coolant bypass valve.

9.

Reposition the hose clamp and remove the turbocharger outlet coolant hose from the turbocharger.

10. Remove the turbocharger outlet coolant pipe banjo bolt and washers.

11. Remove the turbocharger upper heat shield bolts and remove the turbocharger upper heat shield (Figure  2-9).

12. Remove the turbocharger oil feed pipe banjo bolt and washer and reposition the oil feed pipe out of the way (Figure  2-10).

13. Remove the turbocharger oil return pipe nuts at the top of the flywheel housing.

14. Unplug the vane control solenoid and the vane position sensor.

CAUTION: The oil line must be removed before the turbocharger assembly, failure to do so may result in damage to the oil line.

15. Remove the turbocharger bolts and remove the turbocharger (with the oil return pipe).

WARNING:  If a turbocharger failure is thought to be caused due to lack of oil, the camshaft bearing should be
checked. The numberþ4 camshaft bearing bore feeds the turbocharger oil supply (feed) pipe. If this camshaft bear-
ing spins in the bore, the turbocharger will be starved for oil. This will cause a failure of the turbocharger. Failure
to diagnosis this condition will result in repeat turbocharger failures.

Turbocharger Installation

1.

If a turbocharger has failed, clean any turbocharger debris or excessive oil from the charge air cooler system before installing 
the new turbocharger. Failure to clean debris from the charge air cooler system will cause severe turbocharger and engine dam-
age upon startup. Failure to clean excessive oil from the charge air cooler system may cause an engine runaway condition on 
startup, resulting in severe engine damage.

2.

Install the oil feed pipe, washer, and the bolt, if necessary tighten the bolt to 34þN·m (25þlbþft).

3.

Using a new seals, place the turbocharger assembly on the engine block and secure with three bolts. Torque the bolts to
108þN·m (80þlbþft).

4.

Install the turbocharger oil return pipe nuts at the top of the flywheel housing tighten the nuts to 25þN·m (18þlbþft).

5.

If installing a NEW turbocharger, add about 120-150þcc (4-5þoz) of clean engine oil in the turbocharger oil feed pipe opening
while rotating the impeller.

6.

Position the oil feed pipe to the turbocharger.

7.

Install a NEW turbocharger oil feed pipe washer and the banjo bolt tighten the bolt to 34þN·m (25þlbþft).

8.

Install the left exhaust pipe and install the left exhaust pipe to turbocharger bolts tighten the bolt to 53þN·m (39þlbþft).

9.

Install the right exhaust pipe and install the right exhaust pipe to turbocharger bolts tighten the bolt to 53þN·m (39þlbþft).

10. Install the exhaust outlet pipe and tighten the clamp to 15þN·m (11þlbþft).

11. Install the exhaust outlet heat shield and install the remaining exhaust heat shield bolts tighten the bolts to 8þN·m (71þlbþin).

12. Install the turbocharger outlet coolant pipe banjo bolt and washers tighten the bolt to 26þN·m (19þlbþft).

13. Install the turbocharger upper heat shield install the turbocharger upper heat shield bolts and tighten the bolt to 9þN·m

(80þlbþin).

14. Install the charged air cooler inlet duct connector to the turbocharger tighten the charged air cooler inlet duct connector to the

turbocharger clamp tighten the clamp to 6þN·m (53þlbþin).

15. Install the charged air cooler outlet duct to the intake and tighten the charged air cooler outlet duct to intake hose clamp tighten

the clamp to 6þN·m (53þlbþin).

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 Engine  2-19

5745804

16. Install the right turbo pipe and tighten the bolts to 53þN·m (39þlbþft).

17. Install the left turbo pipe and tighten the bolts to 53þN·m (39þlbþft).

18. Install the turbo pipe heat shields and tighten the bolts to 8þN·m (71þlbþin).

19. Install the engine cover, the center console, the right side crash pad, the upper crash pad.

20. Fill the cooling system.

21. Perform the turbocharger learn procedure.

.

Figure 2-7:   Exhaust Down Pipe

Figure 2-8:   Turbo Pipes and Heat Shield

TURBOCHARGER

PIPE

CLAMP

PIPE

CLAMP

EXHAUST

DOWN

PIPE

~

TURBO

PIPES

TURBO

PIPE

HEAT

SHIELD

11-1-05

2-20

Engine

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Figure 2-9:   Turbo Heat Shield

Figure 2-10:   Oil Feed Pipe

 Turbocharger Diagnosis

PROBLEM

POTENTIAL CAUSE

CORRECTION

Low Power 
Poor Accelera-
tion (Black 
smoke not evi-
dent at 1/2 to 
wide open
 throttle)

1.

Lean fuel mixture caused by insufficient fuel 
volume or pressure.

1.

Problem is in fuel delivery system. Check fuel 
supply pump pressure, look for leaks in lines 
and at fittings, plugged fuel filter, accelerator 
cable problem, injection pump problem. Refer 
to low power information in guides for standard 
diagnosis.

TURBO

CHARGER

TURBO

CHARGER

HEAT

SHIELD

OIL

FEED

PIPE

BANJO

BOLT

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 Engine  2-21

5745804

Low Power, 
Poor Accelera-
tion (Black 
smoke evident 
at 3/4 to wide 
open throttle)

1.

Air filter plugged.

1.

Replace filter.

2.

 Restriction in air intake duct to turbocharger 
compressor wheel.

2.

Remove and inspect duct components. Remove/
repair any restrictions.

3.

Air leak in turbocharger compressor inlet and 
outlet ducts. May be accompanied by high 
pitch whine indicating system air leak.

3.

Disassemble, inspect, repair worn, damaged or 
loose parts.

4.

Air leak at intake manifold.

4.

Tighten loose bolts. Or, remove manifold and 
replace gaskets if necessary.

5.

Exhaust leak between cylinder head ports and 
turbine inlet of turbocharger.

5.

Check exhaust manifolds pipes and turbo-
charger connections for leaks. Replace damaged 
components, tighten loose fasteners.

6.

Turbocharger damaged internally.

6.

Remove and inspect turbocharger. Replace if 
compressor/turbine wheels or other internal 
components are damaged.

7.

Fuel system problem (over-rich mixture).

7.

Refer to low power information in standard 
diagnosis.

Turbocharger 
Noise

1.

Obstruction in air intake or outlet systems may 
cause high pitch whine.

1.

Disassemble and clear blockage or restriction.

2.

Compressor/turbine impeller contacting housing, 
or other internal damage. May be accompanied 
by vibration.

2.

Replace turbocharger.

Blue Exhaust 
Smoke with 
Warm Engine 
Only

1.

Insufficient intake air volume.

1.

Disassemble, inspect and clear any restrictions. 
Replace damaged, worn ducting parts.

2.

Partially plugged oil drain tube.

2.

Remove and clear tube. Replace tube if fully 
plugged, pinched or kinked.

3.

Oil Leaking past worn compressor or turbine 
side seals.

3.

Replace turbocharger.

4.

Engine problem caused by worn rings or valve 
seals.

4.

Overhaul cylinder heads or engine as needed.

 Turbocharger Diagnosis

PROBLEM

POTENTIAL CAUSE

CORRECTION

11-1-05