Jeep Liberty KJ. Manual — part 937
REMOVAL
CHARGE AIR COOLER INLET HOSE
1. Open and support hood of vehicle.
2. Loosen hose clamps at both ends of charge air
cooler (CAC) inlet hose.
3. Remove CAC inlet hose (3) from turbocharger and
CAC.
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CHARGE AIR COOLER OUTLET HOSE
1. Raise and support hood on vehicle.
2. Loosen hose clamps at both ends of charge air
cooler (CAC) outlet hose (5).
3. Remove hose (5) from CAC and intake manifold
inlet.
INSTALLATION
CHARGE AIR COOLER INLET HOSE
1. Install charge air cooler (CAC) inlet hose on turbocharger and CAC.
2. Tighten hose clamps.
3. Close hood.
CHARGE AIR COOLER OUTLET HOSE
1. Install charge air cooler (CAC) outlet hose on CAC and intake manifold inlet.
2. Tighten both hose clamp on CAC outlet hose.
3. Close hood.
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TURBOCHARGER
DESCRIPTION
CAUTION: The turbocharger is a performance part
and must not be tampered with. The wastegate
bracket is an integral part of the turbocharger.
Tampering with the wastegate components can
reduce durability by increasing cylinder pressure
and thermal loading due to incorrect inlet and
exhaust manifold pressure. Poor fuel economy
and failure to meet regulatory emissions laws may
result. Increasing the turbocharger boost WILL
NOT increase engine power.
The turbocharger is an exhaust-driven supercharger
which increases the pressure and density of the air
entering the engine through the charge air cooler. With
the increase of air entering the engine, more fuel can
be injected into the cylinders, which creates more
power during combustion.
The turbocharger assembly consists of four (5) major component systems
•
Turbine section
•
Compressor section
•
Bearing housing
•
Variable veins
•
Actuator
OPERATION
Exhaust gas pressure and energy drive the turbine,
which in turn drives a centrifugal compressor that
compresses the inlet air, and forces the air into the
engine through the charge air cooler and plumbing.
Since heat is a by-product of this compression, the air
must pass through a charge air cooler to cool the
incoming air and maintain power and efficiency.
Increasing air flow to the engine provides:
•
Improved engine performance
•
Lower exhaust smoke density
•
Improved operating economy
•
Altitude compensation
•
Noise reduction.
The turbocharger is lubricated by engine oil that is
pressurized, cooled, and filtered. The oil is delivered to
the turbocharger by a supply line (2) that is tapped
into the engine block. The oil travels into the bearing
housing, where it lubricates the shaft (1) and bearings.
A return pipe (3) at the bottom of the bearing housing,
routes the engine oil back to the crankcase.
The most common turbocharger failure is bearing failure related to repeated hot shutdowns with inadequate “cool-
down” periods. A sudden engine shut down after prolonged operation will result in the transfer of heat from the
turbine section of the turbocharger to the bearing housing. This causes the oil to overheat and break down, which
causes bearing and shaft damage the next time the vehicle is started.
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Letting the engine idle after extended operation allows the turbine housing to cool to normal operating temperature.
The following chart should be used as a guide in determining the amount of engine idle time required to sufficiently
cool down the turbocharger before shut down, depending upon the type of driving and the amount of cargo.
TURBOCHARGER
(
COOL DOWN
(
CHART
Driving
Load
Turbocharger
Idle Time (in minutes)
Condition
Temperature
Before Shut Down
Stop & Go
Empty
Cool
Less than 1
Stop & Go
Medium
Warm
1
Highway Speeds
Medium
Warm
2
City Traffic
Max. GCWR
Warm
3
Highway Speeds
Max. GCWR
Warm
4
Uphill Grade
Max. GCWR
Hot
5
REMOVAL
1. Disconnect negative battery cable.
2. Remove engine cover (Refer to 9 - ENGINE - REMOVAL).
3. Disconnect the MAF and Inlet air pressure sensors wiring harness connectors, disconnect the air outlet duct from
the turbocharger, and remove air cleaner assembly (Refer to 9 - ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - REMOVAL).
4. Remove charge air cooler inlet hose from turbocharger (Refer to 11 - EXHAUST SYSTEM/TURBOCHARGER
SYSTEM/CHARGE AIR COOLER AND PLUMBING - REMOVAL).
5. Drain cooling system.
6. Remove coolant recovery pressure container (Refer to 7 - COOLING/ENGINE/COOLANT RECOVERY PRESS
CONTAINER - REMOVAL).
7. Disconnect the turbocharger actuator vacuum hose and position aside.
8. Remove turbocharger upper heat shield.
9. Raise and support the vehicle.
10. Remove the lower splash shield.
11. Disconnect the front exhaust pipe from the turbocharger.
12. Remove the turbocharger support bracket.
13. Disconnect turbocharger oil return line at turbocharger.
14. Lower the vehicle.
15. Remove the turbocharger oil supply line.
16. Remove turbocharger to exhaust manifold retaining nuts and separate turbocharger from exhaust manifold.
CLEANING
All old gaskets should be inspected for any tears or signs of prior leakage. If any gaskets show such indications,
they should be replaced with new gaskets. All gasket mating surfaces must be cleaned of old gasket material to
produce a smooth and dirt free sealing surface for the new gasket.
INSTALLATION
1. Connect turbocharger to exhaust manifold with new gasket. Torque retaining nuts to 32 N·m.
NOTE: After Tightening The Exhaust Manifold To Specification Using a Diagonal-Cross Pattern, Retrace The
Pattern Checking The Correct Torque Value Again.
2. Install exhaust manifold and turbocharger assembly with new gasket in position on studs in cylinder head. Install
retaining nuts and torque to 36 N·m.
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