My brick is getting hot when I drive at speed, 60 mph, for three or four minuets. I took out the radiator and blasted out the fins, and flused it as well as cleaning out he air condensor. The fan clutch seems to be working correctly, cycles as you would expect, and the pusher fan on the front of the condensor also is working. If I turn the heat on, the car cools right down.

Is my radiator shot? Water pump is new, all hoses are new, and everyhting seems to be working correctly. THe syestem doesn't seem to have abnormal pressure or anything. Seems to be the original radiator at 128,000 miles. It would make sense to me that this is the problem, since it only happnes when you are going down the raod, and isn't realy more likely to heat up at a stop or in traffic. what do you guys think?

Thanks in advance

Peter