I need some help! I changed the thermostat and it worked for a about 60 miles then it wanted to start to overheat. filled the radiator porperly with fresh coolant checked the hoses leading to the radiator upper and lower. No signs of leaks. The piece where the thermostat goes, i noticed spray marks from radiator fluid. coming out by the hose. Ant suggestions it has 61,000 miles on it. I really need this fixed I have to go on a long drive in a couple of days!