Hi, earlier on today i noticed that my engine was running a little too hot, so i re-filled the engine coolant with de-ionised water. When i was driving i noticed that my exhaust was ratling when i accelerated and changing into 2nd gear was also a bit rattly and problematic. I managed to make it home with the car and i noticed that there was a trail of water (i think, 90% sure) running behind the car. I was just wonder if this has caused any kind of permanent damage. What should i fill the engine coolant with as im now sure its not just water? Many thanks