GMC 1993 Suburban Owner's Manual page 241

l P 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:
8
Climb a long hill on a hot
day.
0
Stop
after high speed driving.
Q
Idle for long periods in traffic.
e
Tow a trailer.
If you get the overheat warning with no sign of steam,
try
this for a minute
or so:
1. If you have an air conditioner, turn it off.
2.
Turn on your heater to full hot at the highest fan speed and open the
3. If you're in a traffic jam, shift to M (Neutral).
window as necessary.
If you no longer have the overheat warning, you can drive. Just to be safe,
drive slower for about ten 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, push the accelerator until the engine speed
is
about twice as fast as normal idle speed. Bring the engine speed back
to
normal idle speed after two or three minutes. Now see i f the warning stops.
But then, i f 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.
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