A control system according to the principles of the present disclosure includes an estimated coolant flow module and at least one of a valve control module and a pump control module. The estimated coolant flow module estimates a rate of coolant flow through a cooling system for an engine based on a pressure of coolant in the cooling system and a speed of a coolant pump that circulates coolant through the cooling system. The valve control module controls the position of a coolant valve based on the estimated coolant flow rate. The pump control module controls the coolant pump speed based on the estimated coolant flow rate.