What/Where is the "additional water pump"?

[robspeed325i]

Im trying to finish an order for *ALL* the coolant hoses on my 1991 325i. autohausaz says there are two hoses for the "additional water pump" that are NOT listed on either RealOEM or bmwfans.info...

64211376137
64211380012

wtf? Sorry Im a newb, but does my car even *have* an "additional water pump??

the RealOEM page shows the pump, and two hoses, but no part numbers...

http://www.realoem.com/bmw/showparts.do?model=1413&mospid=47322&btnr=64_0133&hg=64&fg=18

[SpecM]

I've never heard of that before

[jlevie]

I believe the secondary water pump for the heater was an option. A bit of investigation in the engine bay (follow the hoses to the firewall) will tell if you car has that option.

[Knockenwelle]

If you enter your correct last 7 digits into RealOEM, it automatically knows exactly what parts your car does and does not have. Although it will still appear on the diagrams, anything your car was not originally equipped with will not show up in the list underneath with a part number. Example: for my auto>5sp swap, I had to use a generic E30, cause if I put in my VIN and tried to search for manual trans parts like shifter, bracket, etc, nothing showed up.

Aux water pump may have been a cold-weather option?

[SpecM]

I believe the secondary water pump for the heater was an option

that's what I'm thinking too