Old coolant begins to break down merely because of the conditions within the engine, being heated and cooling down all of the time. And it can become polluted with dirt and rust particles. Eventually this causes damage to the inside of the engine and radiator, it can clog passages causing the engine to overheat, and cause the engine block and radiator to rust badly from the inside out.
Coolant is typically changed every 30,000 - 50,000 miles.
This should happen automatically. Are you losing coolant, is the cooling system leaking somewhere? Have you just changed the coolant? Unless there is a leak, the system should purge by itself.
As far as i am aware, Vdubs don't need to have the coolant changed. And if you do happen to have the coolant changed make sure you only use the red stuff. That crap that says it works for both red and green i wouldn't trust. As i am sure you may know how expensive parts can cost for Vdubs, so i don't think you wanna mess anything up and have to replace it. I have a 01 GTI VR6 and have never changed coolant in it. You just mainly have to make sure it has the proper amount in it.
Have the coolant changed immediately and you will be ok.
Because it doesnt want to.
The coolant will not protect the cooling system against corrosion.
The correct coolant is DEXCOOL it has an orange color to it. If your coolant is green the coolant has been changed. It has been found out that DEXCOOL was bad for Aluminum heads and gaskets. Best to switch to the green coolant.
Heat will flow from the coolant into the air.
An Spirit engine doesnt use any spacific type of coolant, as long as its a 50/50 mix.
Low coolant? Thermostat not closing allowing engine temperature to get to normal operating range? System air bound? Heater core plugged or restricted? Water pump not circulating coolant?
THe fluid will need flushed and changed.
It is not rust, but broken down extended life coolant. When Extended life coolant goes beyond the replacement time, every five years, it can break down and turn into a rusty sludge like substance. I would bet if you haven't changed the coolant in the car, it has never been changed.