Uh oh, coolant problem, help needed - pics inside [Archive] - Bimmerfest - BMW Forums

: Uh oh, coolant problem, help needed - pics inside

10-22-2008, 04:00 PM
This past weekend while driving (1994 540i - M60), the car suddenly filled with the distinct odor of coolant burning off of hot engine parts. I pulled over and shut the car down and found that a hose had come loose. I loosened the clamp and refitted it back on and wondered why there was such a tiny lip to fasten it to (less than 1/4" sticking out from the housing). I got it home, topped off the coolant and figured that was that.

The next day the hose popped off again, so I repeated the process and it happened again today. This time I took a closer look at why I couldn't reattach it and found that it's not supposed to be a small lip, it's really a protrusion that the hose would normally slide over. In my case, it appears that protrusion has snapped off inside the hose. Now I think I'm screwed. Is there any way to repair this without replacing the entire unit? (what is that thing anyway?) Is it possible to connect two hoses together with a coupler and plug the holes left in the unit? Any help would be appreciated, it's my only transportation and it's obviously incapacitated with this situation. The cheapest possible solution is ideal :) Thanks in advance for any advice!



10-22-2008, 04:15 PM
Thats called the water valve. It distributes the water to your heater radiator.

WATER VALVE Part# 64118391417 Sugg Retail: $158.47

I got the above info at:


10-22-2008, 08:06 PM
yep, thats what it is, or otherwise know as the auxillary waterpump. pain in the butt, however, it is aaccessable relatively easy and swappable with little fuss.
Good luck with it!


10-23-2008, 12:07 PM
I am very grateful for the responses and the help identifying the part in question. I was able to find a used heater valve with the aux pump for under $50 and I suppose I'll spring for that one if I must but I'm particularly interested in bypassing the system all together if its only function is to regulate hot air for the cabin. In Florida as long as the A/C works I'm fine, I don't need the vents to blow hot air... I'll just turn on the seat warmer if I need to. :)

I found some semi-vague instructions while searching here that showed the diagram in the link Lanc3r kindly provided with the hoses colored differently in order to show where they start and terminate. However, I'm struggling a bit at figuring out flow directions and what would connect to what in order to just wholly isolate the heater/water valve so that I'm not obligated to replace it and therefore not have to a) pay b) wait for the part. If anyone can shed any light on the process of doing the actual bypass or is able to indicate flow for the hoses, I would be most appreciative!

10-23-2008, 12:23 PM
This is the picture I was referring to.


10-23-2008, 01:51 PM
so to do this with out spending money
look at the picture as you read, it makes sense to me.


take the red hose off the pump. follow the light blue hose to the vlave. take that hose off and then put the red hose onto that spot.

bypassed pump and everything will still work and you wont loose any coolant

10-23-2008, 02:15 PM
Hrmmm... I follow what you're saying. Regrettably, the pump itself seems to be fine it's the valve that is damaged and unable to accept a hose connection where the light blue hose attaches to the valve -- that sleeve is snapped off inside the hose. As I see it I either need to suck it up and buy the valve just for the sake of having something to attach a hose to or figure out a way to have the whole assembly bypassed to the extent that coolant doesn't even reach it (and hence not leak out the hole in the valve that I can no longer attach a hose to). Thanks for the suggestion, I'm gonna keep poking at it. I welcome any other suggestions as well. :)

10-23-2008, 02:24 PM
In it's simplest form... taking the red hose from the pump and the red hose from the firewall and coupling them together... any adverse effects or would that achieve the result I am seeking?

10-24-2008, 09:58 PM
thats it.

bypasses the entire system. just plug up the pipes for your heater core. dont want to get anything in there just in case you want to have heat at some point.

10-28-2008, 12:44 PM
From Autohausaz, that part costs less than 100$ before shipping.


WATER VALVE Part# 64118391417

10-28-2008, 06:57 PM
Thanks for finding that part cheaper, luckily it turns out I didn't need it after all. Once I got everything apart I found that the part that actually was broken off was the inlet on the aux water pump -- where the bottom red hose in the above picture connects to -- rather than the heater valve so I'm glad I didn't order that right away. As it sits right now I have the system bypassed and no leaks or adverse effects to be seen so far. If I ever put it all back together I'll have to get the pump and from what I've seen it's not as costly as the valve. Thanks to all for the valued input!

bimmer dot info
10-29-2008, 06:20 AM
I've been runnning without the pump for over 2 years. It is not an important part. Only difference I notice is that the heat is a bit weaker at idle.