The aluminum core radiators WILL plug up if MBZ antifreeze is not used, and used with distilled water. Many /most 'green stuff' antifreeze formulations have 'silicone/silicate' corrosion inhibitors, and this stuff reacts with hardness in the water to make solid deposits that plug the passages. The only way to clean it out is to have a competent radiator shot take it apart and rod it out. New tanks can easily be installed. A rod out +top tank will cost (here in Houston ) about $125, not a whole lot less than a new 'after marker identical to OEM unit'

Best preventive is use distilled water and MBZ antifreeze.