I've an '03 Zafira 16v 1.8 Petrol and reckon, going by other posts, that the water pump runs off the timing belt. I'd had the timing belt changed 25k ago. If it does run off the timing belt, should I get both the timing kit + water pump done at same time? I might be wrong, but with a quick check under the hood, I'd thought that the water pump ran off the alternator belt. It might be different engine specs. If not, what does run off the alternator belt?