hear is my story hopefully someone can help.my wife's 99 ford taurus wagon would not blow heatthis fall.a local mechanic and i noticed the coolant was terrible looking so we drained it and removed the heater hose ,made a fitting and backed flusshed the heater core untill clean water came out.we refilled it with water only and had to spend a lot af time getting the air out but were sucsessfull and everything worked fine.good heat the problem started a few days laterwhen i drained the water and filled the system with coolant.it will only produce proper heat at high rpm only cold air at idle.can anyone help
wife very unhappy wearing carharts and longjohns to drive

 

I had the same problem, impeller blades insidemy water pump was rusted out so badit was causingthe coolant not to flow...Your problem could be something else, but that my 2 cents...