Systems and methods for preventing engine overcooling

A cooling system for a marine engine, the cooling system comprising:

• a heat exchanger;
• a coolant pump connected between the marine engine and the heat exchanger;
• a coolant temperature sensor configured to generate a signal based on a temperature of coolant;
• an electronically-controlled bypass valve connected downstream of the coolant pump, the bypass valve including an inlet and a pair of outlets that are both connected upstream of an air cooler, one of the outlets being configured to close a fluid path that connects the coolant pump and the heat exchanger;
• and
• an electronic control module configured generate a command for controlling a state of the bypass valve based on the signal from the coolant temperature sensor.

A method for controlling a cooling system for an internal combustion engine, the method comprising:

• pumping coolant in a first loop for cooling an interior of the internal combustion engine;
• pumping coolant in a second loop for cooling air supplied to the internal combustion engine;
• determining, with an electronic control module, whether the internal combustion engine is in a low load state or a low temperature state based on a plurality of different load thresholds or a plurality of different temperature thresholds;
• and
• in response to determining that the internal combustion engine is in the low load state or the low temperature state, generating a signal to close a portion of the second loop.