Q: What causes the coolant to become too hot?

Your car is relatively new and the mileage is not that high so it’s somewhat surprising to hear that it is overheating. You first want to check and be sure the radiator is full and the reservoir (coolant overflow tank) has coolant too (between "L" and "H" in reservoir when engine is cold). Check to be sure the radiator cap is on properly and the sealing area is free of debris. The cap keeps the system under pressure allowing the cooling system to perform its job.

If there is coolant and the cap is good, you’ll want to consider obvious possible faults such as a non functioning cooling fan, a stuck cooling system thermostat, and/or a faulty water pump which includes the possibility of a loose drive belt.

There are other possible causes including engine management (tuning) issues such as excessively lean operation. Occasionally, brakes can be found to be dragging, tires severely under-inflated, and even transmission faults. If you desire a cooling system diagnostic a certified professional from YourMechanic will evaluate the most likely possibilities first and then move on to all other potential causes until the root cause is found. Hope to have the opportunity to help you with this issue you are having.