Deleting Auxiliary Water Pump?

[e46mpwrd]

Looking at the FSW_PSW.pdf, ZUSATZWASSERPUMPE(Auxilary water pump) to nicht_aktiv looks like the only change needed. Can any one else confirm? Gonna code it tonight. Been a year without it but like everyone else, doubt they'd code it and have it not do much.

[e46mpwrd]

Looking at the FSW_PSW.pdf, ZUSATZWASSERPUMPE(Auxilary water pump) to nicht_aktiv looks like the only change needed. Can any one else confirm? Gonna code it tonight. Been a year without it but like everyone else, doubt they'd code it and have it not do much.

I can confirm myself. This is all that is needed.

[elbert]

Bumping this thread up...

Unlike non-M cars, the cooling system on ours is self-bleeding. Does deleting this aux water pump affect this at all?

[George Hill]

I'm running it as well, coded it as described in Obioban's diy on the old forum. Works fine and clears the CSL airbox. I even snipped off the extra plug. Anyone know the other endpoints of those wires by the way? I'd like to pull them ...

Edit: One wire ends pin 6 on the plug on the back of the heating controls:

The other makes its way to fuse 62 in the glovebox, but so does the water valve wire, and they're the same colors ... and it's unclear where they join based on the wiring diagram.

The other wire (water pump B+) does go to the fuse box, it is in the same fuse location as the valve. The pump terminal goes into the fuse box and has a tab that sticks up. There is a second slot above the primary and the valve terminal goes into there and clips onto the tab. To remove it you have to completely disassemble the fuse box, remove the valve and pump terminal then reinstall the valve terminal in the lower slot.

*If you just cut the terminal off in the engine bay that wire will 100% be hot, just a fyi.

[0-60motorsports]

Very interesting but I think I won’t bother since I have no one to code it for me and I don’t want to lose all my CSL coding.

[ac427]

A bit late in the day but is the purpose of the pump change just to gain a little more space for the CSL airbox?

[Altaran]

A bit late in the day but is the purpose of the pump change just to gain a little more space for the CSL airbox?

Not really necessary for space. I did it for the weight savings.

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[Cubieman]

A bit late in the day but is the purpose of the pump change just to gain a little more space for the CSL airbox?

Potentially can leave a bit more room for the dipstick, I bent mine and it rubs on that valve a bit.

[sapote]

I'm curious of why the engineers needed to add this pump to the heater system, as the non-M cars use the belt driven pump to push coolant thru the heater core and it's more than enough. Electric pump for the heater sounds like a hassle and reliability for no reason as I understand.

[ac427]

Potentially can leave a bit more room for the dipstick, I bent mine and it rubs on that valve a bit.

It is possible to get it to fit. You can rotate the dipstick and keep the pump on its 3 rubber mountings.

I've only just managed to get it to fit properly after 14 years of running a CSL airbox

Before that the pump was hanging on one mount and the dipstick tube was bent and cable tied.

[0-60motorsports]

It is possible to get it to fit. You can rotate the dipstick and keep the pump on its 3 rubber mountings.

I've only just managed to get it to fit properly after 14 years of running a CSL airbox

Before that the pump was hanging on one mount and the dipstick tube was bent and cable tied.

Do you have pics of the way you did it? Im going to order the non M/CSL pump and fix the dipstick location accordingly.

[uberchris]

I'm curious of why the engineers needed to add this pump to the heater system, as the non-M cars use the belt driven pump to push coolant thru the heater core and it's more than enough. Electric pump for the heater sounds like a hassle and reliability for no reason as I understand.

IIRC it's there to circulate coolant in case you want to run the heater for a bit after you shut off the engine. I've always thought it was an odd choice to put it on the m3.

[Obioban]

IIRC it's there to circulate coolant in case you want to run the heater for a bit after you shut off the engine. I've always thought it was an odd choice to put it on the m3.

How do you even activate it on the M3?

As in, on my e39 M5 I could press "rest" to do that-- E.g. run the heat while pumping gas. I don't know of any button on the M3 that fires that function up when the car is off.

[uberchris]

How do you even activate it on the M3?

As in, on my e39 M5 I could press "rest" to do that-- E.g. run the heat while pumping gas. I don't know of any button on the M3 that fires that function up when the car is off.

I'm going off of memory here of the diagnostic function in ISTA back when I was having trouble with it, but I believe the pump comes on automatically when:

1. Ignition On or ACC
2. Engine coolant temperature above some threshold
3. IHKA call for heat

[Obioban]

I'm going off of memory here of the diagnostic function in ISTA back when I was having trouble with it, but I believe the pump comes on automatically when:

1. Ignition On or ACC
2. Engine coolant temperature above some threshold
3. IHKA call for heat

That doesn't seem useful for keeping your wife warm while pumping gas, like the "rest" button