Disclosed are two-valve, split-layout engine cooling systems, methods for making and method for operating such cooling systems, engine coolant valve assembly configurations, and vehicles equipped with an active thermal management system for cooling select powertrain components. A disclosed thermal management system includes a radiator for cooling coolant fluid, and a coolant pump for circulating coolant fluid received from the radiator. A set of conduits fluidly connect the coolant pump to an engine block, a cylinder head, and an exhaust manifold. Another set of conduits fluidly connect the engine block, cylinder head, and exhaust manifold to the radiator, coolant pump, and one or more oil heaters. A first valve assembly is operable to regulate coolant flow between the coolant pump and the radiator. A second valve assembly is operable to regulate coolant fluid flow, individually and jointly, between the engine block, cylinder head, exhaust manifold, radiator, coolant pump, and oil heater(s).