Hi, maybe someone who's done the coolant change can opine here. Thanks in advance for any help.
I own a '07 328i steptronic, decided to change coolant at 100k miles. Followed ENINTY's diy here: http://www.e90post.com/forums/showthread.php?t=248187
Now, to my recollection, my only deviation was I decided not to unhook the hose to the thermostat. Instead, I followed some others suggestion and blew out additional coolant with air, through the reservoir opening. Seemed to work but I bet I didn't get everything as the car only took a gallon and a half of 50/50 BMW coolant / distilled water. Had the bleed screw open and eventually got overflow. Didn't really seem to gulp air or bubble though.
Proceeded with the venting process. Seemed to go fine. Reservoir cap on, bleed screw tightened the exact number of turns I loosened when filling. After the first venting, opened cap, no real hissing and the reservoir didn't appear to need more coolant.
Proceeded to vent a second time. Same result. No need to add any coolant. The level indicator didn't appear to move much at all, and now my reservoir is slightly overfilled.
So I'm wondering if I missed a step. Started car in driveway let it run for about 15 minutes, no signs of distress, leak etc.