Buick RIVIERA 1993 Manual page 199

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, 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
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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