My experience:
My Indy just did the valley pan/coolant pipe job.
He changed out the water pump. It had 100K miles.
Impeller was original factory install plastic.
No leaks, was in decent shape. Just a preventative maintenance item.

2004 X5 4.4

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2003 4.6is X5
2003 525it
2003 E53 X5 Standard shift