Dodge RAM 1500 1998 Owner's Manual page 361

7 - 46 ENGINE
ENGINE COOLANT THERMOSTAT - 3.7L/4.7L (Continued)
1 - THERMOSTAT HOUSING
2 - THERMOSTAT LOCATION
ENGINE COOLANT
THERMOSTAT - 5.9L DIESEL
DESCRIPTION
CAUTION: Do not operate an engine without a ther-
mostat, except for servicing or testing. An engine
with the thermostat removed will operate in the
radiator bypass mode, causing an overheat condi-
tion.
The thermostat of the 5.9L diesel engine is located
in the front of the cylinder head, underneath the
thermostat housing (Fig. 25).
The same thermostat is used for winter and sum-
mer seasons. An engine should not be operated with-
out a thermostat, except for servicing or testing.
Operating without a thermostat will cause overheat-
ing.
OPERATION
The wax pellet is located in a sealed container at
the spring end of the thermostat. When heated, the
pellet expands, overcoming closing spring tension
and water pump pressure to force the valve to open.
Fig. 24 Thermostat and Thermostat Housing 3.7L/4.7L
3 - THERMOSTAT AND GASKET
4 - TIMING CHAIN COVER
Fig. 25 Thermostat–5.9L Diesel-Typical
1 - THERMOSTAT HOUSING
2 - CYLINDER HEAD
3 - THERMOSTAT
DR