my car is over heating and it does it when im at idle too. Do you think it is my therm. not opening up, or could it be the water pump. And when it over heat i mean it heats up as far as it can go..i tried turing on the heat on high and it still did not cool down. If anyone can give a somthing i would appreciate it.

 

Well Tbird, assuming that the cooling system is full and water pump is being turned by drive belt then a thermostat would be the most likely suspect. It is the cheapest part and usually the easiest to replace. Are the cooling fans coming on when it is starting to overheat? If they are not then could be a faulty fan temp sensor or fan. Also check to see if the radiator is getting hot as well as the upper and lower radiator hoses. Cold spots on the radiator face could mean a restricted or plugged radiator.