deletion of aux water pump ?

[autobahnjim]

hey guys, im curious . when the b35 was introduced, the coolant manifold ( rear of head pt#11121253208 )
that was in use on the b34s was deleted and an aux water pump was added to increase or maintain coolant flow.
has anyone retro fitted the b34 coolant manifold and subsequently deleted the aux water pump ?
it would seem that the adding rear coolant manifold would aid in the reducing the hot spots that are common on b35s.

any thoughts or experiences ?

rthanks...jim

[Binjammin]

Pretty sure Demet_K did it.

[nonturbodan]

I took the one off of my 540. I figured if anything I would lose some heating capacity at idle but I can't tell a difference. I don't know if the M30 powered e34 would behave any differently.

[moroza]

Mine's been disabled for years and I never notice (M62). The first one I had in there broke, and if this one does I'm just going to bypass it.

[Neel]

There are a bunch of guys on Mye28.com that have done b35 swaps to their b34 cars, and a high number of them have done this. I would try posting in there but before you do that I would search and read that forum. I am considering doing this as well.. but haven't started looking into it. I do know that the consensus over there seems to be the b34 cooling routing on a b35 seems to be better, and reduces the risk of HG failure on the b35.

[shogun]

According to the German language tech training info the aux water pump is just for heating the interior. The aux water pump is just a comfort item to feed always a constant flow of hot coolant to the heater core, 950 l/h and the aux water pump motor has 11W. The aux pump only switches on when the heating system is switched on and a temperature of 30 degree Celsius of the coolant is reached.
Downside without aux water pump: it will heat less when engine runs in idle or low RPM, because now the main water pump supplies coolant (warm) to the heater core depending on the engine RPM, as the water pump is belt driven and the aux water pump is electric driven = independent from the engine RPM.
See section 5.8 page 38 ( large file, >2 MB ) http://www.e38.org/e32/klimaautomatik.pdf

[demetk]

I did this retrofit on the b35 turbo and eliminated the maze of b35 hoses in favor of the b34 setup. The aux water pump was also eliminated as it wasn't needed anymore since the rear gooseneck provided good coolant flow directly to the heater valve. Coolant flow out of the gooseneck is interrupted by the heater valve when there is no call for heat, like on a hot summer's day.

[Neel]

http://www.bimmerforums.com/forum/archive/index.php/t-2084407.html

[demetk]

This one is better, www.bimmerforums.com/forum/showthread.php?2084407-E28-M30-gooseneck-pics

[E38740iMD]

where is the aux water pump on the b35?

[Layne]

where is the aux water pump on the b35?

It's not on the engine. It's mounted to the bottom of the heater valves.

[E38740iMD]

It's not on the engine. It's mounted to the bottom of the heater valves.

ok thanks, i knew you it wasnt on the engine but i never saw this external water pump

meant to say where in a b35 powered e34

[shogun]

always mounted below the heater valves http://bmwe32.masscom.net/johan/watervalves/watervalves.html