Purpose of a electrical aux water pump?

Wellingtonz · 03-24-2023, 01:41 AM

car is a 2013 118i F20 N13.

it has a mechanical main water pump and a electrical aux water pump.

what does the aux pump do exactly? I google and it says it's for when the heater is on? so is that the only purpose?

I saw some wetness around it so I'm wondering...

IJO · 03-24-2023, 02:25 AM

Often used to keep coolant circulating around the head and watercooled turbo to prevent heat soak damage. It's shut off when the coolant temp drops to a safe level.

All petrol turbos I've driven (Alfa, DS3 and 116i) have had one.

03-24-2023, 01:41 AM	#1
Wellingtonz Private 1 Rep 76 Posts Drives: bmw 118i f20 n13/ 320i F30 N20 Join Date: Aug 2022 Location: Singapore iTrader: (0)	Purpose of a electrical aux water pump? car is a 2013 118i F20 N13. it has a mechanical main water pump and a electrical aux water pump. what does the aux pump do exactly? I google and it says it's for when the heater is on? so is that the only purpose? I saw some wetness around it so I'm wondering...
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03-24-2023, 02:25 AM	#2
IJO Second Lieutenant 22 Rep 218 Posts Drives: BMW 116I F20 Join Date: Apr 2022 Location: UK iTrader: (0)	Often used to keep coolant circulating around the head and watercooled turbo to prevent heat soak damage. It's shut off when the coolant temp drops to a safe level. All petrol turbos I've driven (Alfa, DS3 and 116i) have had one.
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