Electric Water Pump For BMW 135i/335i/535i/640i/740i/X5/X6/Z4 35i (N54/N55)

1. How does this electric water pump work?

Many new energy vehicles like RVs and other special vehicles often use this electric water pump in micro water pumps as water circulation, cooling or on-board water supply systems.

The circular movement of the motor makes the diaphragm inside the water pump reciprocate through the mechanical device, thereby compressing and stretching the air in the pump cavity (fixed volume).

Under the action of the one-way valve, a positive pressure (actual output) is formed at the drain port. The size of the pressure is related to the boost received by the pump outlet and the characteristics of the pump); a vacuum is formed at the pumping port, resulting in a pressure difference compared with the external atmospheric pressure.

Under the action of the pressure difference, the water is pressed into the water inlet and then discharged from the drain. Under the action of the kinetic energy transmitted by the motor, the water is continuously sucked and discharged to form a relatively stable flow.

2. What are the common problems occuring to this pump, and why this part is highly recommended as a good part for BMW spare parts dealers?

BMW owners find this pump fail quite frequently. Problems like plastic housing where rotor sits cracked all over and both terminals from resistor burnt by look and smell occur a lot.

Because it's electric, when it fails it does so completely and without warning, and it is recommended to be replaced before 80,000 miles.

BMW makes this electric pump to reduce emissions and make the engine more efficient, but as it is plastic, its heat resistance capacity is not that good. That's why it often fails and needs replacement.

However, repairing this pump costs long time and much money(around 800 usd). One only needs to spend less than 300 usd to get a re-manufactured part by Sacer, looking like a brand new one.

3. What are the advantages of Sacer's Pump compared with those served by aftermarket supplier?

Sacer's re-manufactured electric pump uses high-temperature resistant material, serving as a perfect replacement solution for original BMW electric water pump.

Below is the comparison of this pump made by Sacer and other aftermarket suppliers.