BMW 525i Problem Report
BMW 525i Coolant Leak From Radiator
It is not uncommon for the radiator to develop a coolant leak. A leaking radiator will require replacement. When a leaking radiator is replaced the entire cooling system should be inspected and if any additional leaks are found they should be repaired also.
Overheating can cause severe engine damage. If the engine begins to overheat it is recommended to stop at the first available location and have your vehicle towed to a repair shop.