Is it bad to drive car without radiator working?

Answer 1

EXTREMELY !!! The radiator is the heat exchanger for the engine. The coolant absorbs heat caused by combustion and is circulated to the radiator by the water pump. The core of the radiator allows the cooling fan and normal air movement while driving, to pass over the fins of the radiator core. This cools the temperature of the coolant before it returns to the engine. Excessive heat in the engine can cause oil breakdown and sludging, which can block oil flow, resulting in terminal failure of the engine. If the car has an aluminum cylinder head, the excessive heat could cause the cylinder head to warp and the headgasket to fail. Headgasket failure can allow coolant to enter the oiling system and cause the engine to seize up. Coolant entering the combustion chamber due to a failed headgasket, can cause the engine to hydro-lock and damage pistons or connecting rods and again, engine failure!