My advice. Pay Chevy the 97 bucks to diagnose it. It is WELL WORTH it. But from the brief description. Bad head gasket. What you describe is EXACTLY what happens.
No heat
loosing coolant
NOW it might not be. Could be a leak in the heater core or a hose too. The one symptom you don't have is the dancing temperature needle.
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Wednesday, February 17th, 2010 AT 8:08 AM