Thanks for the input everyone. I went ahead and ordered a water pump, thermostat, and expansion tank from FCP.

I think its kind of sad that a lot of people say these cars shouldn't idle long. I have 3 other vehicles which are older with WAY more mileage that i have let idle for hours on a regular basis with no ill effects. They aren't BMWs though. :)

Just had a look at some live data on my N63 - specifically oil temperature - it sits at around 112C which to me seems a little on the high side of the scale reinforcing the ‘dont let it idle’ concept - this coupled with high coolant temps (105C thermostat) adds up to very high underhood temps not to mention the placement of primary cats (3-400C).
Lots of plastic parts plus heat cycles = timebomb from a design point of view. That being said, they are great performers but need regular checkups to make sure they keep singing sweetly. My 2c


2012 E70 5.0iX