GMC 2003 C4C042, Owner'S Manual

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5-19
If No Steam Is Coming From Your Engine
An overheat warning, along with a low coolant light,
can indicate a serious problem. See “Low Coolant
Light” in the Index.
If you get an engine overheat warning with no low
coolant light, but see or hear no steam, the problem may
not be too serious. Sometimes the engine can get a little
too hot when you:
D Climb a long hill on a hot day.
D Stop after high
-
speed driving.
D Idle for long periods in traffic.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. In heavy traffic, let the engine idle in neutral while
stopped. If it is safe to do so, pull off the road, shift
to park or neutral and let the engine idle.
2. Turn on your heater to full hot at the highest fan
speed and open the window as necessary.
3. If climbing a hill, downshift to raise engine and
fan speeds.
If you no longer have the overheat warning, you can
drive. Just to be safe, drive slower for about 10 minutes.
If the warning doesn’t come back on, you can drive
normally.
If the warning continues and you have not stopped, pull
over, stop, and park your vehicle right away.
If there’s still no sign of steam, you can push down the
accelerator until the engine speed is about twice as fast
as normal idle speed for at least three minutes while
you’re parked. If you still have the warning, turn off
the engine and get everyone out of the vehicle until it
cools down.
You may decide not to lift the hood but to get service
help right away.