Cooling issues....

[NewB2dsm]

My Car is overheating on long pulls like 3rd and 4th. Then cools back down if i start to drive normal again. The Lower radiator house is ice cold, top is hot. So then I replaced the thermostate with new one. Same thing, put old, thought to be broke thermostat into boiling water and it opened. Again lower radiator hose is cold, top is hot. What is the problem?

 

[Old Mitsu Tech]

Well, it could be a limed up radiator, water pump not circulating water properly, or something of that nature. Are both of the heater hoses hot? I'm wondering about circulation. If both heater hoses are hot, I would have the radiator tested for flow problems. I've seen this repeatedly in the smaller radiators. Being a plastic and aluminum radiator, you most likely will be purchasing a new radiator. I prefer the all metal ones and purchased a 90 Eclipse this year with an all metal radiator. So I know they exist. Check the radiator first. If this is not it, we can always check the water pump although it's not much fun to change it. If you do by chance pull the water pump, I think it can go without saying, change it since you are already there. I would.
Let me know.

Good Luck