If you are experiencing problems with your heating system, it’s important to check all of the components. One of these components is the heater core. If you bypass the heater core, you may experience problems such as a lack of heat, water leaking into the system, or a fire. By checking all of your components and fixing any issues before they become bigger problems, you will be able to improve your heating system and stay safe.
If you have a heat exchanger that has been bypassed, you will have trouble cooling the vehicle down because the thermostat is sending coolant to the bypass, and the bypass is preventing coolant from flowing to the radiator. If you continue driving, the coolant will be forced through the bypass and eventually flood the engine, causing severe damage.
Why bypassing the heater core could cause engine overheating?
During operation, ripped hoses restrict the coolant flow rate to the heater core, so you are limited to the amount of coolant the water pump delivers. By relying on the control hose to replace the heater hose (Supply & Return), you remove the restrictions on coolant flow. This higher coolant flow rate is being stolen from the coolant flow that this water pump provides to the engine. This decreased engine coolant flow means decreased engine maximum cooling capability. Under lighter engine loads, such as when driving at a slower speed, it’s not much of a problem. Under higher loads, like highway driving, it could cause engine overheating. Blocking the water flow via the heater core will increase the engine’s cooling capacity.