on mine the water pump and expansion tank were replaced at 85K miles or so by a BMW dealer. They checked out the whole system and the radiator and everything else checked out. A few of the hoses were also replaced. The car was also checked by a BMW dealer at 95K for a PPI and the entire cooling system checked out OK at that time as well. Car is still fine at 111K miles, but I plan to do the radiator in the next few months just in case.

__________________
2003 4.6is - SOLD
2003 M5 Imola
2008 Mini Cooper S
2011 Mazda CX9