ENGINE COOLANT THERMOSTAT
DESCRIPTION
DESCRIPTION - 3.7L ENGINE
CAUTION: Do not operate an engine without a
thermostat, except for servicing or testing.
A pellet-type thermostat (5) controls the operating tem-
perature of the engine by controlling the amount of
coolant flow to the radiator. On all engines the thermo-
stat is closed below 195°F (90°C). Above this temper-
ature, coolant is allowed to flow to the radiator. This
provides quick engine warm up and overall tempera-
ture control. On the 3.7L engine the thermostat is
designed to block the flow of the coolant bypass jour-
nal by 50% instead of completely blocking the flow.
This design controls coolant temperature more accu-
rately.
The same thermostat is used for winter and summer
seasons. An engine should not be operated without a
thermostat, except for servicing or testing. Operating
without a thermostat causes other problems. These
are: longer engine warmup time, unreliable warmup
performance, increased exhaust emissions and crank-
case condensation. This condensation can result in
sludge formation.
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ENGINE
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