I am losing coolant and there are no external leaks. Where could the coolant be going?
The most likely scenarios are an engine leaking internally (e.g.;cracked cylinder head, leaking head gasket, leaking intake gasket, etc.) are the coolant is evaporating before you see it. Modern engine oil can hold a surprising amount of coolant without turning cloudy. Unfortunately, the oil may look normal but coolant destroys the ability to lubricate. Small external leaks are sometimes evaporated by the heat of the engine and do not drip. Other possible causes are a water pump that only leaks when running and the fan is dispersing the leak. Leaks at the heater core can also be difficult to find as they can drip with the evaporator water and be quite diluted. Adding florescent dye to the coolant and using a black-light might help located the source. For more information on GM V8 engines, please see our Detailed Topic GM Coolant Loss with No Apparent Leak.
