|
It's been six years (only 15k miles) but its time based, not mileage based for coolant, same as brake fluid. Coolant additives get used up and lose their anti corrosion and anti freeze properties. (brake fluid is hydroscopic, so absorbs moisture, which lowers the boiling point and can cause corrosion of the cylinder bores in the calipers and master cylinder)
I asked the BMW dealer to change the coolant when I had my final free oil and cabin filter change at the four year point, but they said they "tested it" and it was fine. Not sure what test was conducted...but surprised they turned me down.
I'm having my coolant changed (G48) in my 2018 M550iX in a few weeks, I just made the appointment with my trusted independent BMW service provider. He will change both the engine coolant and the intercooler circuit as well. Total cost with coolant, labor and all those disposal and shop fees (plus 10.3% WA State tax) comes to around $290. I doubt the dealer is much more, but have had a mixed experience with them.
|