Good diagnostics on your solo thread. The aux water pump helps move coolant through the heater cores when the motor is turning slow. With it not running you'll probably find it won't heat the car very well unless the revs are up on the engine.
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'04 X5 3.0 5AT with 300,000+km - Black
'08 535xi 6AT with 290,000+km - Titanium Silver
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