Antifreeze and Engine Coolant
Grand Am GT

What does it mean when the coolant in overflow tank is boiling?

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Wiki User
June 05, 2007 4:00PM

Engine is overheating. it could also just be that your radiator cap is bad and allowing the pressure to release too soon. Keep an eye on your temperature gage, if is showing hot or over heated then check coolant level and possibly water pump problem or head gasket, if not overly hot then suspect the radiator cap.