What is a common cause of engine overheating?

A common cause of engine overheating is insufficient coolant levels. The engine relies on coolant to absorb heat and maintain an optimal operating temperature. When the coolant level is low, it cannot effectively transfer heat away from the engine, leading to a rise in temperature. This situation can be caused by a leak in the cooling system, a malfunctioning radiator, or simply not refilling the coolant after maintenance.

While excessive oil levels can cause some issues, it does not directly affect the engine's ability to cool itself. Faulty spark plugs mainly affect ignition and engine performance rather than temperature regulation. Similarly, dirty air filters can impair air intake and engine performance, but they do not directly cause overheating. Therefore, insufficient coolant is the primary factor in this scenario that leads to engine overheating.