Removal-3.9L/5.9L Engine

WARNING: This page is about a different car, the 2003 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: DO NOT LOOSEN RADIATOR DRAIN-COCK WITH SYSTEM HOT AND PRESSURIZED. SERIOUS BURNS FROM COOLANT CAN OCCUR.

Do not waste reusable coolant. If solution is clean, drain coolant into a clean container for reuse.

If thermostat is being replaced, be sure that replacement is specified thermostat for vehicle model and engine type.

Factory installed thermostat housings on 3.9L and 5.9L engines are installed on a gasket with an anti-stick coating. This will aid in gasket removal and clean-up.

Disconnect negative battery cable at battery.
Drain cooling system until coolant level is below thermostat (Refer to STANDARD PROCEDURE ).
Air Conditioned vehicles: Remove support bracket (generator mounting bracket-to-intake manifold) located near rear of generator (Fig 1).

Fig 1: Removing generator mounting Bracket
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NOTE: On air conditioning equipped vehicles, the generator must be partially removed.
Remove accessory drive belt (Refer to DRIVE BELTS ) (Fig 2).

Fig 2: Automatic Belt Tensioner - 5.9L Engines
Courtesy of DAIMLERCHRYSLER CORP.
Remove two generator mounting bolts. Do not remove any wiring at generator. If equipped with 4WD, unplug 4WD indicator lamp wiring harness (located near rear of generator).
Remove generator. Position generator to gain access for thermostat gasket removal.
WARNING: CONSTANT TENSION HOSE CLAMPS ARE USED ON MOST COOLING SYSTEM HOSES. WHEN REMOVING OR INSTALLING, USE ONLY TOOLS DESIGNED FOR SERVICING THIS TYPE OF CLAMP, SUCH AS SPECIAL CLAMP TOOL (NUMBER 6094). SNAP-ON CLAMP TOOL (NUMBER HPC-20) MAY BE USED FOR LARGER CLAMPS. ALWAYS WEAR SAFETY GLASSES WHEN SERVICING CONSTANT TENSION CLAMPS.

CAUTION: A number or letter is stamped into the tongue of constant tension clamps (Fig 3). If replacement is necessary, use only an original equipment clamp with matching number or letter.

Fig 3: Identifying Spring Clamp Size
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Remove radiator upper hose clamp and upper hose at thermostat housing.
Position wiring harness (behind thermostat housing) to gain access to thermostat housing.
Remove thermostat housing mounting bolts, thermostat housing, gasket and thermostat (Fig 4). Discard old gasket.

Fig 4: Identifying Thermostat Housing, Gasket And Thermostat

Courtesy of DAIMLERCHRYSLER CORP.