At My Witts End

It doesn't seem old enough to be suffering from core fin separation but it may depend on the environment it has lived in. If the fins lose their bond to the tubes in the radiator core they will not transfer enough heat out into the fins/air. I have seen it a few times but it's usually on older equipment. Usually starts at the lower sides. The fins will easily pull right off the tubes. Real bad ones will just flak apart. The complaint was the same as they described.

When did this start was it gradual or more sudden?