HELP!!!!!! I recently changed the alternator on my 01 530i and a buddy told me to "burp" the system. Squeeze the coolant lines while the car was running with the expansion tank lid off. Did that 5 times. Heard nothing similar to a burp, produced 0 bubbles. Thought i was ok till today. Heat wasn't working well. I was idling waiting for my wife to finish work and then the steam bath started. I quickly shut everything down and called for a ride. What the hell do I need to do now. PLEASE HELP!!!!!!