Thanks ENINTY. Very clear write up.
I just did mine and have one comment:
Originally Posted by ENINTY
....The BMW TIS procedure calls for removing the lower radiator hose that goes into the front of the thermostat housing. That hose has the funky BMW plastic coolant hose fitting and is a PIA to get loose.....
That fitting is a quick-disconnect coupler and is actually very easy to detach:
1. Pull the wire lock to the unlocked position. The wire lock is hard to reach from above so it's easier to pry from below and push the tabs up using a small flat screw driver.
2. Pull the fitting away from the thermostat housing. Warning: the fitting can break loose suddenly.
To reinstall the fitting:
1. Check condition of the o-ring inside the fitting.
2. Push the wire lock down to the locked position.
3. Push the fitting onto thermostat housing. The wire lock should audibly snap into place.