If it is the original 2001 water pump, and I was doing the thermostat, I would do the water pump and all hoses at the same time. The hoses would be more important to me than the water pump.

I don't know what the seller you are referencing means by refurbished. If it was fixed, or a spray can rebuilt, I would stay away. If it was remanufactured, then that is what I would pick. I would also expect that options to be cheaper, net of the core charge when you return the old water pump core (if your core is acceptable).

If you look at the ECS Tuning site, under engine, cooling system, water pump, you will see photos of four water pumps. Two of the metal impellers look like cheap stampings that are tacked together. Those are what I would avoid, as they can break. The Graf pump is that cheaper impeller, at least in the ECS pictures. One of the other metal impellers looks robust, but heavy. The composite impeller on the OE pump looks the best to me. Best coolant flow, and longest lasting. Just look at the vane design. It is worth looking at the zoomed photos of the vanes on each pump. Look at the open area that passes coolant, and how restricted it is on some designs. Look at the spot welds. Look at the rough edges of the casting on the heavy impeller.

The Stewart pump vane design looks good as well, but the pump is too expensive.

Link here: OEM / Performance Parts for Audi, BMW, Mercedes Benz, Mini, Porsche & Volkswagen - ECS Tuning

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
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