Installation; Charge Air Cooler And Plumbing Description; Operation; Diagnosis And Testing - Charge Air Cooler System - Leaks - Jeep 2002 WJ Service Manual

11a - 4 EXHAUST SYSTEM AND TURBOCHARGER - 2.7L DIESEL
WASTEGATE (Continued)

INSTALLATION

(1) Position and install waste gate solenoid onto
bracket.
(2) Connect engine vacuum harness to waste gate
solenoid
(3) Connect waste gate solenoid electrical connec-
tor.
(4) Connect negative battery cable.
CHARGE AIR COOLER AND
PLUMBING
DESCRIPTION
The charge air system consists of the charge air
cooler and charge air cooler piping.
The charge air cooler is a heat exchanger that uses
air flow from vehicle motion to dissipate heat from
the intake air. As the turbocharger increases air
pressure, the air temperature increases. Lowering
the intake air temperature increases engine effi-
ciency and power.

OPERATION

Intake air is drawn through the air cleaner and
into the turbocharger compressor housing. Pressur-
ized air from the turbocharger then flows forward
through the charge air cooler located in front of the
radiator. From the charge air cooler the air flows
back into the intake manifold.
DIAGNOSIS AND TESTING - CHARGE AIR
COOLER SYSTEM - LEAKS
Low turbocharger boost pressure and low engine
preformance can be caused by leaks in the charge air
cooler or it's plumbing. The following procedure out-
lines how to check for leaks in the charge air cooler
system.
(1) Loosen clamp and remove turbocharger to air
inlet duct rubber sleeve from turbocharger.
(2) Insert Special Tool 8442 Adapter into the rub-
ber sleeve. Tighten existing clamp to 8 N·m (72
in.lbs.).
CAUTION: Do not apply more than 138 kpa (20 psi)
air pressure to the charge air cooler system, sever
damage to the charge air cooler system may occur.
(3) Connect regulated air supply to air fitting on
Special Tool 8442 Adapter. Set air pressure to a Max-
imum of 138 kpa (20 psi).
(4) Using soapy water check the air inlet ducts,
rubber sleeves, charge air cooler and intake manifold
for leaks.

REMOVAL - CHARGE AIR COOLER

WARNING: IF THE ENGINE WAS JUST TURNED
OFF, THE AIR INTAKE SYSTEM TUBES MAY BE
HOT.
NOTE: Note the location of the rubber air charge
cooler to A/C condenser and air charger cooler to
radiator air seals. The seals are use to prevent
overheating and improve charge air and A/C effi-
ciency.
(1) Disconnect the battery negative cables.
(2) Remove cooling module (Refer to 7 - COOLING/
ENGINE/RADIATOR - REMOVAL).
(3) Remove the front grill.
(4) Mark the position of the radiator upper cross
member and remove cross member.
(5) Unbolt the transmission auxiliary cooler and
power steering cooler from the charge air cooler and
set aside.
(6) Remove the boost tubes from the charge air
cooler.
(7) Remove power steering reservoir retaining bolt,
and set reservoir aside.
(8) Remove the charge air cooler bolts.
NOTE: Care must be taken not to damage the
charge air cooler fins and the fins of other ancillary
cooler components.
(9) Pivot the charge air cooler rearward and up to
remove.

CLEANING

CAUTION: Do not use caustic cleaners to clean the
charge air cooler. Damage to the charge air cooler
will result.
NOTE: If internal debris cannot be removed from
the cooler, the charge air cooler MUST be replaced.
(1) If the engine experiences a turbocharger failure
or any other situation where oil or debris get into the
charge air cooler, the charge air cooler must be
cleaned internally.
(2) Position the charge air cooler so the inlet and
outlet tubes are vertical.
(3) Flush the cooler internally with solvent in the
direction opposite of normal air flow.
(4) Shake the cooler and lightly tap on the end
tanks with a rubber mallet to dislodge trapped
debris.
(5) Continue flushing until all debris or oil are
removed.
WG