What is "Auxiliary Water Pump For Heating System"? - picture inside

[BMWlover]

During searching Bavarian auto.com, I found something strange:

I know what a water pump is.

BUT! what is "Auxiliary Water Pump - For Heating System"?
(Refer to the attached pic)

Please share some of your expertise!

Thanks~ [bmwkick]

 

[Rudy]

I'm guessing here: Maybe it's for the residual heating function? It might move water through the heater core when the engine is off and the REST button is pressed.

Is it for an E39? I don't think earlier models had that feature.

 

[Ghost]

The auxiliary coolant pump is electrically operated and offers additional coolant circulation to the heater core. I changed mine due to a leak that fogged up the driver’s side of the windshield on my ’89 535. It’s located in the rear of the engine compartment under the heater valve (right next to the fuse box).

 

[BMWlover]

Aha~ I got it. I think the aux coolant pump has brought some problem to my car. Thank you!!

The auxiliary coolant pump is electrically operated and offers additional coolant circulation to the heater core. I changed mine due to a leak that fogged up the driver’s side of the windshield on my ’89 535. It’s located in the rear of the engine compartment under the heater valve (right next to the fuse box).

 

[Ghost]

Happy to help.

 

[uscharalph]

Ghost, where did your pupple accumulate. I've got the same steam / fog on the driver's side as well a a little leak. I thought it was the heater core, but maybe it's the aux water pump (Much less labor).