Originally Posted by weasel56

At the dealer all we do is fully drain the radiator and block as this gets 90+% of the coolant out. The blue coolant used in BMW's is great coolant that holds up very good and protects against corrosion and electrolysis better than any over the counter coolant. In newer vehicles they call it "lifetime" coolant, even though it is the same coolant. I guess BMW figures the coolant will still get changed out when there is a component failure like water pump or thermostat.

But if you are like me, you will still do regular flushes/exchanges just as good maintenance. If you want to make extra measures to protect your system, refill it with new BMW coolant and distilled water when you do it.

It is also a good idea to operate your heater every so often to get fresh coolant into it, rather than it sitting unused 3/4's of the year with the same coolant/water sitting stagnant in it.