coolant "flush"
 

All posts I've found here only cover "draining" (from radiator and engine block) the coolant but not really flush the coolant. How does BMW technician flush the coolant? Use the flush kit connecting to household water hose? Or this kind of flush isn't required on BMW? But aren't there some passages that coolant won't come out completely in the draining process?

I guess BMW coolant doesn't need to be flushed out?? just draining it out is good enough?

There is really no need to change the coolant unless you have 100K or change a major component on the motor (i.e. head gasket/water pump).

I believe it should be changed every 4 years. It should be one of the maintenance jobs in inspection II.

My '04 user's manual states "lifetime" fluid that never requires changing.

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.

thanks a lot! it's good to have someone working in dealer here. always get great insider info. ;)

does anyone have a DYI for coolant flush & thermostat. 3.0 x5
thanks...mark