need info help plz, when I was driving yesterday the car started to slow down and made a grinding noise maybe from the engine or transmission not to sure happened twice like a loud grinding noise slowing down the car rappidly like it was seizing up or something. Thought maybe it was the coolant lvl not sure so i topped it off and drove him with out this occuring again. what could it be????? 2001 bmw x5 4.4i