The radiator should be hot and even pretty much everywhere. Cold spots indicate blockage, the water is flowing so slowly the air gets it very cool. A good two row radiator is adequite, but even in good shape all aren't created the same. I had a rebuilt one in my 80 633 that always ran cool, a rebuilt one in a Bavaria that sometimes heated up in town, but had fatter tubes and was cool in the desert with A/C and a 528i that was only so so with a brand new radiator both in town and on the highway. Mike