Buick 1998 Century Owner's Manual page 237

If No Steam Is Coming From Your Engine
If you get the overheat 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:
0
Climb a long hill on a hot day.
0
Stop after high-speed driving.
0
Idle for long periods in traffic.
Tow a trailer.
If you get the overheat warning with no sign of steam,
try this for a minute or so:
1. Turn off your air conditioner.
2. Turn on your heater to full hot at the highest fan
3. If you're in a traffic jam, shift to NEUTRAL (N);
otherwise, shift to the highest gear while
driving -- AUTOMATIC OVERDRIVE
(@).
speed and open the window 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 doesn't come back on,
you can drive normally.
If the warning continues, pull over, stop, and park your
vehicle right away.
If there's still no sign of steam, you can idle the engine
for two or three minutes while you're parked, to see if
the warning stops. But then, if you still have the
warning, turn ojfthe engine and get everyone out o f the
vehicle until it cools down. Also, see "Overheated
Engine Protection Operating Mode" listed previously in
this section.
You may decide not to lift the hood but to get service
help right away.
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