Dodge RAM 1500 1998 Owner's Manual page 360

DR
ENGINE COOLANT THERMOSTAT - 3.7L/4.7L (Continued)
Fig. 23 Thermostat Cross Section View 3.7L/4.7L
1 - FROM HEATER AND DEGAS CONTAINER
2 - FROM RADIATOR
3 - TO WATER PUMP
4- THERMOSTAT
indicated by the instrument panel gauge or by poor
heater performance unless a DTC is present. Refer to
the Diagnosis section of this group for other probable
causes.
The DTC can also be accessed through the
DRBIII scan tool. Refer to the appropriate Power-
train Diagnostic Procedures information for diagnos-
tic information and operation of the DRBIII
tool.
REMOVAL
WARNING: DO NOT LOOSEN THE RADIATOR
DRAINCOCK WITH THE COOLING SYSTEM HOT
AND PRESSURIZED. SERIOUS BURNS FROM THE
COOLANT CAN OCCUR.
Do not waste reusable coolant. If the solution is
clean, drain the coolant into a clean container for
reuse.
If the thermostat is being replaced, be sure that
the replacement is the specified thermostat for the
vehicle model and engine type.
(1) Disconnect the negative battery cable.
(2) Drain the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(3) Raise and support the vehicle.
(4) Remove the splash shield.
(5) Remove the lower radiator hose clamp and the
lower radiator hose at the thermostat housing.
(6) Remove the thermostat housing mounting
bolts, thermostat housing and thermostat (Fig. 24).
INSTALLATION
(1) Clean the mating areas of the timing chain
cover and the thermostat housing.
(2) Install the thermostat (spring side down) into
the recessed machined groove on the timing chain
cover (Fig. 24).
(3) Position the thermostat housing on the timing
chain cover.
(4) Install the housing-to-timing chain cover bolts.
Tighten the bolts to 13 N·m (112 in. lbs.).
CAUTION: The housing must be tightened evenly
and the thermostat must be centered into the
recessed groove in the timimg chain cover. If not, it
may result in a cracked housing, damaged timing
chain cover threads or coolant leaks.
(5) Install the lower radiator hose on the thermo-
stat housing.
(6) Install the splash shield.
(7) Lower the vehicle.
(8) Fill the cooling system (Refer to 7 - COOLING
- STANDARD PROCEDURE).
(9) Connect negative battery cable.
(10) Start and warm the engine. Check for leaks.
scan
ENGINE 7 - 45