Honda 2004 Civic Si Owner's Manual page 61

Gauges
Temperature Gauge
This shows the temperature of the
engine's coolant. During normal
operation, the pointer should rise to
about the middle of the gauge. In
severe driving conditions, the pointer
may rise to the upper zone. If it
reaches the red (Hot) mark, pull
safely to the side of the road. Turn to
page 174 for instructions and
precautions on checking the engine's
cooling system.
58
Instruments and Controls