overheating advise

First of all I've already seach and have not find any help. So guys I've been having some problems with my GST that I recently bought. First of all the car was sit for about one year. Now that I'm driving the car it overheats every time I get out of the freeway. The gauge needle goes up to 3/4 near the red line. I took out the thermostat, and did a radiator flush and it still doing the same thing. My question is this should I replace the radiator and put a thermostat or just put the new radiator with out the thermostat. If any one can advise me thanks..

unless your radiator is leaking, there is no reason to replace it. Try replacing coolant temp sensors.

Well the radiator is not leaking, but the water boils.. Do you think the radiator might be plug cause when I flush it for the first time the water was very dirty like corroded..

Does your fan come on???

yes both of them are fine..

are you getting any smoke.

replace the radiator cap, its not holding pressure-water boils and car overheats.

no I don't get any smoke. I'm going to replace the radiator cap $ see what happends

The car is still doing the same thing.. what else should I do..

are you leaking/low on oil? out in left field question but ::Shrugs:: it could be the case. i know my car runs a little hotter when i don't change the oil fast enough.

Are you loosing any coolant at all.

My bet would be on a blockage.

I am not totally a hundred percent sure but I think when this was happening to my friends car it was because the water pump wasing working properly. I think i was still working but not pushing enough through to cool the engine. Just a thought. Correct me if I am wrong though.