m5runner, When changing engine coolant you are to use BMW coolant and Di-ionized water or distilled water but not tap water. This is pure H2O with out all the additives or correct ph to get the job done. I am starting to think my surging may be my brakes. I have had them on for a couple of months now. I didn't bleed them when I replaced the rotors and pads. My car is pulling a little to the left ever since the change. Why I say the brakes when I start off on the car and come to my first stop it doesn't do the surging but by the time I hit another stop and the brakes are making some heat it starts. I don't know how to confirm for sure.
