Hi, My S4 is going to my main dealer for an oil leak to be sorted under warranty. I asked them to give me an idea of what extra cost is involved in doing the timing belt at the same time, as I understand that a fair deal of engine dismantling work will be required get to the oil leak. What else is worth changing at the same time ? One respected specialist said that the idler won't need changing (although I think I will anyway). What about the water pump or other belts ?