i have a 96 rs with a 3.8 it runs hot when i go 35 mph but if i go faster than that it over heats i replaced the thermostat and it ran fine for 2 days but now it blows cold air instead of heat can somebody please help me it well be very much appriciated

 

should be the water pump. not turning or something.

 

Fill it with coolant. There is a little plastic elbow that goes from the intake manifold to the tensioner assembly, that I would check for leaks. It is common for these to become brittle and crack.