Hybrid cooling system of an internal combustion engine

A coolant system of a vehicle, comprising:

• a cylinder head coolant circuit including a first loop controlled by a shut-off valve arranged downstream of a heat exchanger and upstream of a pump, the pump to pump coolant through a head coolant jacket before reaching the heat exchanger, a second loop including a thermostat to control coolant flow from a main cooler to the pump;
• a cylinder block oil circuit including a control element arranged upstream of a variable oil pump, the heat exchanger arranged downstream of the variable oil pump, the variable oil pump to pump oil through the heat exchanger to a block coolant jacket;
• and
• a control system including instructions to:
• close the shut-off valve to block flow through the coolant circuit and open the control element to provide a first amount of oil through the oil circuit when a temperature of coolant in a cylinder head jacket is below a first threshold;
• and
• close the thermostat to block coolant flow through the second loop when an inlet coolant temperature is below a third threshold.