I called our dealership and they again told me that we really did not need to change the coolant in our 2008 xB. Should last for ten years. I was wondering if doing something simple like siphoning out the coolant expansion tank and replacing the old coolant with new would keep it fresh. I really do not know how much flow goes though the tank. Does the coolant actually flow through the tank or is it just a storage vessel?

 

There's a replacement scheduled in the owners manual. I think it's at 100,000 miles. There's a drain plug underneath the radiator if you plan on draining it. Make sure the car is cold when you do it. You will have to remove the splash guard.
The coolant does not circulate through the overflow tank. It's there to keep the radiator full and without air bubbles.

 

I also have an 08 with 146k I have not changed the coolant. If the car is not over heating don't change it.

 

Umm, no.