Auxiliary water/coolant pump ...replacement?

[jpilk99]

I'm chasing an issue with my '03 X5 with the 3.0 six cylinder and it's looking like my secondary or auxiliary water/coolant pump may be dead. (Holding out hope that there's a slight chance of the Water Valve, up by the air filter/throttle bottle that may be the issue).

I've looked and looked for DIYs and videos and not finding much, does anyone have a link they can share?

A lot of the videos I did find make it sound like it's the same process for any ol' BMW with the 3.0 six cylinder, but, then comments in/under the video have people losin' their minds because they say it's a completely different, nightmare'ish process on an X5.

Thanks in advance.

Jay

[tttomttt]

well.... what is the issue you are chasing? I had a somewhat hard time bleeding my cooling system until I changed out my aux heat pump. Which by the way is just outside the expansion tank. Easy to replace and inexpensive to replace.

[andrewwynn]

I noticed my coolant pump whirrring away the other day. If after you turn off your car and heater engaged you don't hear a buzz just behind the we expansion tank that might be the problem.


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[jpilk99]

Thank you both! The "issue I was chasing" was this recent post: https://xoutpost.com/bmw-sav-forums/...ylinder-2.html . I was having a hard time successfully bleeding the system. After following all the steps, (and I've bled my 740's, 3-series, etc. a bunch of times), and getting all the air bubbles out of the bleed screw and watching a nice flow out of the little "piss" whole at the top of the expansion tank ...I would still get the "Check Coolant Level" warning after only a few hours of light driving.

So maybe I had something going on that was causing the Check Coolant to keep coming back. Never any noticeable leaks under the vehicle. However, I never heard the sound that is now going on; https://youtu.be/arlkpPqR8KQ and I no longer have any flow of coolant either out the bleed screw or the little hole at the top of the expansion tank. Interesting too, in this short video, when I grabbed the hose I could feel it pulsing/vibrating...

All indicators seem to be pointing to the auxiliary pump. Again, I'm curious if somehow the valve may be bad, but, wouldn't think I'd be getting that sound along with the lack of "flow".

Would really love to see a video or pictures of someone doing a swap - or even the aux pump itself. I got the impression that this video, from the good folks at Bav Auto, was accurate to my X5: https://www.youtube.com/watch?v=o-BpUzAemyQ

Thanks all.

[andrewwynn]

That sounds exactly like a fish tank pump where the impeller is worn and no longer smoothly spins. I'm betting BMW uses the same method of magnetic link from motor to impeller and the impeller is loose and wobbling.


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[jpilk99]

Originally Posted by andrewwynn

That sounds exactly like a fish tank pump where the impeller is worn and no longer smoothly spins. I'm betting BMW uses the same method of magnetic link from motor to impeller and the impeller is loose and wobbling.


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My daughter has about 5 fish tanks and, you're right, it does sound like that!! Sadly, a lot louder and ...worse than any other fish tank pump.

[jpilk99]

Originally Posted by tttomttt

well.... what is the issue you are chasing? I had a somewhat hard time bleeding my cooling system until I changed out my aux heat pump. Which by the way is just outside the expansion tank. Easy to replace and inexpensive to replace.

Hi Tttomttt,

I'm looking all over for this auxiliary water pump, especially around the expansion tank, and I don't see it. Can you tell me exactly where it is? I have a feeling my '03 X5 with the 3.0 six cylinder is different?

Here's a video I just took looking around for it: https://youtu.be/909A0BCCJu4

Here's another as I listen to the sound of the auxiliary pump (I believe) making noise: https://youtu.be/amPXWkn2UD4

Thank you.

Jay

[andrewwynn]

Watching the repair video shows the pump being near the radiator lower hose. (right side of engine below fan).

You would have to look from below with the splash shield removed to see it.


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