I got the car a week ago and on the second day it started overheating (never let it go in the red) I opened the hood and there was alot of coolant sprayed all around. On the next day i got changed upper hose, radiator, and radiator cap. When i went to pick up the car it was running ok for 30-40 min but when stuck in traffic the temp went up again and i returned the car to the mechanic shop for one more check. He said they didn't suck the air from the sistem and after 10 min adding antifreeze with a special funnel he told me to drive a while. I was in traffic maybe for 30-40 min with normal temp on the gauge (below the middle). The car was running good so i went to work - i work pizza delivery so i had to stay in traffic and drive hwy stop and start. I drove 6 hours this way with no problem and on my way home which is 3 min driving the car overheated again. That morning i started it and it warmed up to normal working temp for 5 min and it stayed there for the next 15 min i left it working. I just noticed the upper hose was warm after 15 min and the lower was almost cold. Should it be like this and what might cause the problem with this randomly overheating?