The E36 M3 and Z3M were manufactured with cooling systems made almost entirely out of plastic. With the high temperatures and pressures that the system endures, the plastic tanks and fittings on your radiator can become quite brittle. Over time, your radiator can also have its fins damaged by stones and bugs, reducing the efficiency of the cooling system and causing leaks. 

Please be aware that due to the fragility of radiators, there is often minor fin damage that occurs during the manufacturing process. In most cases bent fins are unavoidable and will not affect the performance of the radiator. If you have any concerns with your replacement radiator, we encourage you to get in contact with us.