Hi there,
The timing belt is a serviced item and should be replaced at 90,000km if it fails you will do serious engine damage, as for the water pump, there is no need to replace it if it is not noisy or leaking, as it is driven by the timing belt, it is often a good time to re new it as it is exposed and require only a few extra minuets work to do while replacing the timing belt, but this is optional, you do not have to replace the pump if you don't want to or if there is no evidence that it it leaking or noisy.
Mark (mhpautos)
Sunday, November 8th, 2009 AT 4:05 PM