Buick 1994 LeSabre Owner's Manual page 197

The coolant level should be at or above "FULL COLD."
If it isn't, you may have a leak in the radiator hoses,
heater hoses, radiator, water pump or somewhere else in
the cooling system.
If the coolant inside the coolant recovery tank is boiling,
don't do anything else until it cools down.
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NOTICE:
I
Engine damage from running your engine
without coolant isn't covered by your warranty.
..
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If there seems to be no leak, check to see if the electric
engine fans are running. If the engine is overheating,
both fans should be running. If they aren't, your vehicle
needs service.
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