Are you seeing coolant on the ground? If so, where, in relation to the engine, are you seeing it? If there are no signs of leakage, your engine is burning it which means you need new head gaskets.
RepairPal Certified shops can diagnose and repair your 2000 Chevrolet Silverado 1500. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.