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Water Pump and Thermostat Replacement

Model: BMW Serie 3 E46 - Years: 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
Part: Pump

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Video tutorial

Open the hood and ensure it is securely supported. The water pump is located at the front of the engine, so you need to remove the air intake duct, the cooling fan cover, and the fan itself.

Then, pry the tensioner to release the drive belt and subsequently remove the drive pulley of the water pump (it is secured with four bolts). Before proceeding with the removal of the pump, it is recommended to drain the coolant through the designated cap (blue) located under the radiator.

Disconnect the rubber hoses and the connector attached to the thermostat, and remove the thermostat assembly (it is located just above the water pump). You can now remove the mounting bolts of the water pump and extract it from its housing.

Insert the new pump and tighten the corresponding mounting bolts. Next, install the new thermostat housing, connecting the hoses and the connector.

Finally, reattach the drive pulley of the pump and the belt. Restore the coolant level (using antifreeze) and reinstall the fan and ducts that were previously removed.

Start the engine, activate the cabin heater, and let it warm up until the fan engages to open the thermostat and check its operation; recheck the coolant level.


Updated on 4 February 2026 by ScegliAuto


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