Coolant Temperature Gauge
Notice: A sudden increase in coolant temperature may indicate engine or cooling system failure. Bring the vehicle to a safe stop and investigate the cause to prevent further damage. Do not operate the engine until the cause has been determined and corrected.
During normal engine operation, the coolant temperature gauge should read 200 to 205°F (93 to 96°C). See Fig.. If the temperature remains below 160°F (71°C) or exceeds 235°F (113°C), inspect the cooling system to determine the cause. See the vehicle workshop manual for troubleshooting and repair procedures.
If the coolant temperature rises above 253°F (123°C), the check engine and stop engine warning indicators will illuminate, and the buzzer will sound. At this point, the engine will derate and idle speed will increase, to speed up the cooling fan and water pump to cool the engine.