More and more vehicles require electric water pumps, such as electric and hybrid vehicles, which experts estimate will be sold at a rate of 3.8 million per year by 2020. These vehicles rely on electric water pumps to cool their batteries. And think of the increasing number of cars outfitted with a turbocharger system. Many of these systems, too, are water cooled and require an electric water pump to function properly. Below, we’ll present some of the unique characteristics of electric water pumps, as well as discuss the results of Gates’ analysis of a large number of failed OE electric water pumps to determine what causes electric water pumps to stop working.
What sets electric water pumps apart from their traditional counterparts?
The main function of electric water pumps – providing standard engine cooling – obviously does not differ from that of traditional accessory-belt-driven and timing-belt-driven pumps, yet the former do have several unique advantages. For starters, while traditional water pumps pump coolant through the entire system, some new vehicles use up to three electric water pumps for various systems. Such segmented cooling reduces the load on the engine and lets mechanics replace only the part that has failed. If, for instance, the electric water pump used for cabin heating breaks down, there is no need to replace the pumps responsible for turbocharger system cooling or battery cooling as well. In addition, electric water pumps can be controlled by sensors to provide the necessary amount of coolant at any time.
What causes electric water pumps to fail?
Gates has analyzed a large number of failed OE products to determine what causes an electric water pump to stop functioning. We’ll outline the most common causes in more detail below, omitting exceptional cases for clarity’s sake, such as a broken-off impeller blade that Gates experts discovered in one electric water pump.
1. Worn down rotating parts
Some of the problems that electric water pumps face are common to belt-driven water pumps as well, such as rotating parts that melt or wear down due to inferior materials.
2. Using the wrong coolant
Standard water pumps are prone to contamination issues, and the same holds true for electric water pumps. Just as with standard water pumps, the use of general, over-the-counter coolant when coolant with specific properties is prescribed can cause the premature failure of electric water pumps – as does mixing coolants with different chemical components or using contaminated coolant.
3. Inadequate external sealing
There is another primary reason for failure that can be traced back to the mounting location of electric water pumps. Several of them are in high heat areas, where the air intermittently heats up and cools down again. The resulting condensation can get into the circuit board, destroy the electronics and, once again, cause the pump to fail.
4. Putting too much demand on the pump
Lastly, the demand put on the pump can simply be too much for the design of its internal components, leading to failure as early as 90,000 to 150,000 kilometers into a vehicle’s life.