Hyundai Repair: 2000 hyundai elantra gls overheating, coolant temperature sensor, hyundai elantra gls

Question
my hyundai is overheating with the coolant in the resiviour tank boiling over and coming out the relief hose.  we went to replace the thermostat and got confused about where exactly it is supposed to be.  we found what looked like part of a thermostat in a part that a diagram for the 2001 model stated it should be at, but when we placed it in there we still had trouble with overheating.  do you have any diagrams for the 2000 model and any advise as to what i should be doing here?

Answer
The thermostat is located in the housing on the end of the upper radiator hose.  When installing the new thermostat, you should make sure that the spring side of the thermostat goes toward the engine.  

I don't have any way to add a diagram, but you can see one in the shop manual at www.hmaservice.com.  You'll need to register for a free account, and the site requires internet explorer.  I found the diagram in the engine coolant temperature sensor component diagram.

Presuming you had no leaks and you've got your thermostat installed correctly, fill the cooling system and start the car with the radiator cap off.  When the car reaches operating temperature, the thermostat should open and you should have coolant flow.  If you cannot tell through the radiator filler neck whether you have flow, then wait until the cooling fan comes on.  At that time, both radiator hoses should be hot and the fan should be blowing hot air.  If the coolant is not flowing, the fan will blow cool air and one radiator hose may be not hot.  

You'll need to check that your cooling fan cycles on and off.  If it doesn't, you'll need to check the cooling fan circuit and the coolant temperature sensor.