Will a bad heater core make a car overheat?

Yes, a bad heater core can cause a car to overheat. The heater core is part of the vehicle's cooling system, and if it is clogged or leaking, it can disrupt the flow of coolant. This inadequate coolant circulation can lead to increased engine temperatures, resulting in overheating. Additionally, if the heater core leaks, it may lead to a loss of coolant, further exacerbating the overheating issue.