You can and some do, especially if they don't know the history of the vehicle or if it is a new but used purchase. If that was the case for me I might do the same, and would be more likely to do so if I was driving a lot of miles each month. No way to challenge the process but since I DIY, most of the time I am in the--- if it's not broken don't fix it.

On the other hand, if the water pump was bad rather than the alternator, I would change the hoses in the area and also the thermostat as they don't cost much and I have the cooling system drained. I would also check any other hoses carrying coolant thoroughly and replace as needed.

I have had my 4.6 since new and have 110,000mi. on it. I have changed one hose, never changed the water pump,thermostat or the alternator.

I wait for most stuff to show symptoms.

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X5 4.6 2002 Black Sap, Black interior. 2013 X5M Melbourne Red, Bamboo interior
Dallas