There is no strange hardware, its just the cars computer doing the work. Some times the computer does this to protect components when its not under a load. I know from past experience that if you rev a engine to high with no load and limit, some part, most likely a piston rod, will fail and...
there is a slight possibility that there is a clog in the system. another possibility is that the water pump is going bad.
your heater is just like a mini radiator for your car. hot coolant is passed through the radiator and a fan blows are through it and it is directed to the cars cabin. this...