Engines with electric auxiliary pumps become more efficient, as they generate less excess heat and oil consumption. Even though not all vehicles have one yet, these pumps are growingly popular in modern, low-emission and high-output engines that have to run within a small temperature range in order to maintain their efficiency.

The usefulness of an auxiliary electric water pump

So, what is an auxiliary water pump? It is a secondary pump that plays a crucial role in maintaining engine efficiency and passenger comfort. These pumps can send hot coolant into the heater core regardless of the engine’s RPMs, providing hot/cold air to the cabin even when the engine is idling or off. The auxiliary coolant pump can continue to operate while the car has stopped, allowing coolant to circulate and fully dissipate the heat from the supercharger.

This type of water pump is essential for passenger comfort, since it allows for sufficient heating even when passengers are driving in traffic or at low RPM. Also, many modern cars use this second pump to allow you to use the air condition for a period while the engine is off. 

Note that unlike the main water pump, this one is not running all the time. The electronic control unit will regulate the auxiliary pump according to the needs of the moment.

To sum up, some of its unique advantages include:

• Facilitates demand-driven cooling of the vehicle.
• Saves on fuel.
• Enhances passenger comfort.
• Is efficient in cooling down power train components.
• Reduces emissions.

Auxiliary electric water pump diagram

Understanding the auxiliary electric water pump diagram is essential to grasp how this component integrates into the vehicle’s cooling system. This pump is typically located near the heater core or within the engine bay and operates as part of the broader coolant circulation system.

A standard auxiliary electric water pump diagram includes the following key components:

• Main coolant lines – Transport coolant throughout the engine.
• Heater core – Receives heated coolant to provide warmth to the cabin.
• Bypass hose – Allows the auxiliary pump to circulate coolant independently.
• Electronic Control Unit (ECU) – Regulates pump operation based on temperature and vehicle conditions.
• Electrical connections – Power and control the auxiliary water pump motor.

The pump activates based on inputs from the BCM (Body Control Module), ensuring coolant circulation even when the engine is off or idling. This contributes to passenger comfort, fuel efficiency, and optimal thermal management of powertrain components.

For a detailed diagram specific to your vehicle, always refer to the manufacturer’s service manual.

Related content: Peculiarities of an auxiliary water pump

Reasons to change your auxiliary electric water pump

The main reason these pumps fail is the electric motor’s natural age and wear. If this does happen, then the heater core will not be able to heat up and replacement will be necessary.

Within age and wear, there are 5 common ways in which electric auxiliary water pumps can fail:

• Weep hole is leaking coolant, indicating that the dynamic seal has failed. 
• The water pump leaking into the engine, making the oil milky and thin.
• Pump’s impeller fails and makes a chirping noise as it contacts the housing.
• The galleries in the water pump become plugged from sludge build-up.
• Electric motor fails due to a short in the wiring, making it inoperable.

Potential complications

A failed auxiliary water pump will almost never cause the vehicle to overheat. However, if inoperative, you might notice some of the following situations during driving:

• No warm air coming from the heater: since its primary job is to supply hot coolant to the heater core, the first symptom of a problem with this component would be no hot air blowing from the heater.
• Heater shows fluctuating heat: the temperature inside the vehicle is increasing or decreasing based on the driving mode, especially if there is a noticeable temperature decrease when the engine is idling.
• Windows defrost is not working: when windows fog up, the defrost mode is in charge of blowing warm air onto the windshield for clear vision. If the pump is failing, the windows will not defrost rather quickly.
• High-pitched buzzing sound: coming from under your dashboard, this might happen if there is an electrical short in the wiring, making the pump run faster than it should or continue to run after the engine is off.

How to replace an electric auxiliary water pump step by step

Once you have verified the condition of the electric auxiliary water pump and confirm its need for replacement, make sure to follow these steps one by one for an optimal replacement. Remember to always consider individual instructions proposed by the vehicle’s owner manual.  

Auxiliary water pump replacement step-by-step:

1. Drain the coolant from the system.
2. Remove any interfering parts, if necessary.
3. Disconnect the auxiliary water pump connector.
4. Remove all the hoses connected to the pump.
5. Remove all the mounting bolts and the auxiliary water pump.
6. Install the new auxiliary water pump and tighten the bolts.
7. Connect again the hoses back.
8. Install all previously removed parts in the reverse order.
9. Fill up the cooling system with indicated coolant to the required level.
10. Bleed coolant system according to the service manual.
11. Check coolant system for leaks.

And that’s it! You are done! 

Remember to always test drive the vehicle by driving it around and monitoring the cooling temperature!

Discover our range extension of Auxiliary Electric Water Pumps

The importance of proper selection of auxiliary electric water pumps

A good quality electric auxiliary water pump will determine the time span of an optimal coolant system and performance in any modern vehicle. These pumps are not only used to make modern engines efficient but have enabled the cooling of batteries in hybrid and electric vehicles.

With a complete range of auxiliary water pumps of more than 60 references, DOLZ offers its customers the best solutions thanks to personalized attention and the latest technology in the manufacture of water pumps for the aftermarket sector.

If you are looking for top-tier auxiliary electric water pumps, contact us and we will provide you with the information and support you need.

La entrada When and how to install an auxiliary electric water pump se publicó primero en Industrias Dolz.

La entrada Peculiarities of an auxiliary water pump se publicó primero en Industrias Dolz.

Main uses and functions of secondary water pumps in vehicles

Secondary water pumps, also known as auxiliary pumps, are the star component in upsetting any vehicle’s cooling system. Even though not all vehicles have one (yet), these pumps are growingly popular as engines become more efficient and generate less excess heat. 

This type of pump is not connected to the main engine cooling system, so it is not running all the time. Instead, it provides supplementary coolant that circulates through a bypass hose to the heater core when needed. Additionally, it guarantees the cooling of the electric motor, and the inverter that electric and hybrid vehicles have.

Secondary water pumps keep the coolant flowing even when the engine is not running, ensuring there is always enough volume of coolant to keep the heater core warm. This enables vehicle engineers to use larger heater cores, allowing for the following features:

Improve driver comfort

Some types of engines, such as diesel-power ones, do not generate great amounts of heat when running or idling. This means that in lower engine speeds, the coolant in the heater core might lose its heat before being passed through the outlet. Adding a secondary coolant pump secures optimum heating even at low speeds.

This is important for passenger comfort, since it allows for sufficient heating even when passengers are driving in traffic or at low RPM. Moreover, an auxiliary water pump can also keep the cabin heated for short periods of time, even after the driver has turned off the ignition.

Maintain battery temperature

Thermal management poses a singular challenge in fully or partially battery-powered vehicles. Modern vehicles with hybrid drive and stop/start systems use batteries that must be kept at a certain operating temperature of engine to remain efficient in the long term. This is where auxiliary pumps come into play, for example to cool down the turbocharge.

The intelligent thermal management in these vehicles relies on several auxiliary pumps, which are turned on by the ECU when needed for a more targeted cooling. These pumps are individually adjustable; each of them is responsible for cooling a different area and can fail or be replaced without affecting the others.

Related content: When and how to install an auxiliary electric water pump

Signs and causes of failure in the secondary water pump

The main reasons why a secondary water pump fails are:

1. Fluctuating heating performance
2. Buzzing sound under the dashboard
3. Age and wear
4. Overheating
5. Low or bad coolant
6. Defective pump or improper installation

Keep reading to know more in depth about them:

1. Fluctuating heating performance

If the secondary water pump in a vehicle is inoperative, it will most probably lead to reduced or fluctuating heater performance at low speeds and at idle. This might also affect window fog, resulting in the defrost mode not working.

2. Buzzing sound under the dashboard

If there is an electrical problem with the secondary coolant pump, the pump might run faster than it should or continue to run after the engine is turned off. This will occasionally result in a high-pitched buzzing sound.

The sound indicates an electrical short in the wiring that powers the engine auxiliary water pump and is a key indicator of a need for replacement.

3. Age and wear

Like all moving and rotating components, brushes wear and windings short. The most common cause of water pump failure is simply from age and wear of its electric motor. Over time, most parts in a car or truck, auxiliary pumps included, start to break down due to constant wear and tear. 

4. Overheating

Overheating issues might affect any water pump’s lifespan. Too much heat in the engine can cause problems with the coolant system. Overheating can hasten the auxiliary water pump’s failure because increased cooling system pressures can force coolant past the shaft seals.

5. Low or bad coolant

Low coolant can cause a pump to fail. If too little coolant is circulating through the circuit, the blower fan will pull enough heat out of the coolant and cause the heater core to get cold. Furthermore, if the fluid in the cooling system is not properly maintained or if it is mixed with improper fluids such as water, corrosion will occur, reducing pump efficiency.

6. Defective pump or improper installation

A defective or improperly installed auxiliary pump will, at some early point, start showing the malfunctioning symptoms outlined in the previous section. Investing in a quality and compatible brand, as well as paying attention to all individual specifications of assembly will ensure the correct functioning of the vehicle’s cooling system.

You may like: Peculiarities of an auxiliary water pump

Guaranteed auxiliary water pumps with a trusted supplier

Industrias Dolz, with almost 90 years of history, is a leader in the manufacture of water pumps. From mechanical and electrical water pumps to variable and auxiliary water pumps.

Currently our range of auxiliary electric water pumps offers more than 70 references, all of them now available, which allows us to cover most of the current fleet of vehicles, fully covering the needs and demands of our customers and allows us to continue expanding our range of products.

This year we launched 28 new references of our auxiliary electric water pumps.

The new secondary water pump references cover the demands of more than 850 vehicle models from brands such as Mercedes-Benz, Audi, BMW, Ford, Porsche, Jaguar, or Opel.

If you want to know more about them, check this post!

And if you are looking for top-tier auxiliary electric water pumps, contact us and we will provide you with the information and support you need.

…yes we have!

La entrada Common causes and symptoms of secondary water pump failure se publicó primero en Industrias Dolz.

+3 Water pumps

New part numbers for water pumps suitable for: Honda, Mercedes-Benz and Audi.

• DOLZ H265 (mechanical water pump); M670 (variable water pump)and EA572A (electric auxiliary water pump).
• GGT PA13275 (mechanical water pump); PA12957 (variable water pump)and PA13402 (electric auxiliary water pump).
  

Based on the extensive knowledge of our experts, at Dolz we have developed a range that is characterized by its reliability, efficiency, and ease of assembly. More than 1,300 water pumps that guarantee the main European and Asian brands coverage and strengthen our leadership position in the market. Therefore, you can be confident that we will have the parts you need when you need them.

+5 part numbers for Timing chain kits

New part numbers for Volkswagen Group, Nissan, Renault, Jaguar and Land Rover applications:

• DOLZ SKCR020; SKCN127; SKCA032V; SKCL028; SKCL029.
• GGT KCSPA020; KCSPA127; KCSPA032V; KCSPA028, KCSPA029.
  
  

Dolz Kits are characterized by their reliability, efficiency and easy-fit mode, being the most competitive timing chain kits on the market. Our complete range includes the Best-Selling references in Europe and includes all the necessary components delivered in one single package to guarantee a professional assembly.

+4 Timing belt kits

New timing belt kits with and without water pump suitable for: Volkswagen Group, Alfa Romeo, Jeep, Lancia and Fiat.

• DOLZ KD248 (with water pump); SKD248; KD301 (with water pump); SKD301.
• GGT KPA20248 (with water pump); KSPA248; KPA20301 (with water pump); KSPA301.

The quality of transmission components goes a long way in determining proper engine performance. That is why the kit format is a solution that guarantees the correct maintenance and synergy of the components and prolongs the useful life, durability, and performance of the entire transmission system. As you know, when replacing components, it is best practice to replace all the associated parts.

Dolz/GGT Kits are designed to provide the driver with the highest performance in any type of condition. We offer a full range that already exceeds 270 PN’s.

Download our latest part numbers! NTR Dolz/GGT september

Dolz, your safety choice since 1934

Industrias Dolz covers more than 90% of vehicle sales in the European market. Thanks to its more than 90 year of experience in the sector, and offers a complete range, providing its customers and partners with the best solutions, excellent quality, service and innovation.

Manufactured to be equivalent to OE quality specifications.

Certifies according to the Quality Management System (SGC) ISO 9001:2015, Dolz/GGT products are designed to cope with the parameters required by modern engine designers and feature OE equivalent components.

Would you like to be the first to receive the latest news about our products and highlights by email? Make sure to subscribe to our monthly newsletter to read more posts like this!

La entrada DOLZ/GGT New-To-Range: +12 new part numbers se publicó primero en Industrias Dolz.

28 new references that cover the demands of more than 850 vehicle models from brands such as Mercedes-Benz, Audi, BMW, Ford, Porsche, Jaguar, or Opel.

As engines become more efficient, less excess heat will be produced, the use of these types of water pumps is increasing.

Its main function is to circulate coolant in auxiliary cooling systems. With new vehicles equipped with mild hybrid systems for advanced start-stop, vehicles need auxiliary electric water pumps not only to improve cabin comfort, but also to keep the batteries at a constant temperature.

Industrias Dolz is one of the main manufacturers of water pumps in the aftermarket sector. Thanks to our knowledge and experience of almost 90 years, at Dolz we integrate the latest technology with coordinated planning and flexible production, which allows us to provide our customers with the best service and quality.

…yes we have!

La entrada 28 new references to our range of auxiliary electric water pumps se publicó primero en Industrias Dolz.