Chevrolet 2007 Cobalt Owner's Manual page 304

If No Steam Is Coming From Your
Engine
An engine coolant temperature warning can
indicate a serious problem. See Engine Coolant
Temperature Warning Light on page 170.
If you get an engine coolant temperature warning,
but see or hear no steam, the problem may not
be too serious. Sometimes the engine can
get a little too hot when you:
•
Climb a long hill on a hot day.
•
Stop after high-speed driving.
•
Idle for long periods in traffic.
•
Tow a trailer.
304
If you get the engine coolant temperature warning
with no sign of steam, try this for a minute or so:
1. If you have an air conditioner and it is on, turn
it off.
2. In heavy traffic, let the engine idle in
NEUTRAL (N) for automatic transaxle
or NEUTRAL for manual transaxle, while
stopped. If it is safe to do so, pull off the road,
shift to PARK (P) or NEUTRAL (N) and let
the engine idle.
3. Turn on your heater to full hot at the highest
fan speed and open the windows as
necessary.
If you no longer have the overheat warning, you
can drive. Just to be safe, drive slower for
about 10 minutes. If the warning does not come
back on, you can drive normally.