What is an auxiliary water pump?
The auxiliary water pump is an electric water pump that helps to send hot coolant to the heater core so that your heater can warm up the cabin of the vehicle on cold days. Engine auxiliary water pumps are a relatively recent innovation in car history (since the late 1980s) and not every vehicle has one, but they have become fairly common in gasoline-powered vehicles.
Unlike your vehicle’s main water pump, which is powered by the drive belt, an auxiliary water pump is electronic, and the motor is electronically controlled.
When should I replace the auxiliary water pump in my car?
You should take your car to a mechanic for an auxiliary water pump replacement if you notice the following symptoms:
Cold air blowing from the vehicle’s heater
Inconsistent heater temperature
Malfunctioning defrost system
Buzzing from underneath your dashboard
When you encounter these symptoms your first thought may be that you have an issue with your thermostat, but these problems are more likely signs of a faulty auxiliary water pump.
How often should an auxiliary water pump be replaced?
Auxiliary water pumps should last as long as your car, but of course, you might still run into issues. The best plan is to stay vigilant and look out for any warning signs that you might have a failing auxiliary water pump.
Can I replace my auxiliary water pump myself?
You can complete an auxiliary water pump replacement at home if you have experience with DIY auto repair, but the replacement is a very involved process. Most drivers should let a professional handle an auxiliary water pump replacement.