[Salzar]

I was told I was leaking from the bottom fitting of my expansion tank so I bought a new one and a new A/T Thermostat and replaced them but now I am unable to keep coolant in it at all! The tank looked fine too, no cracks anywhere, but the coolant is now coming from what I have discovered is the ATF heat exchange box, where the coolant connections are, not coming from the pipes. When I look at it they are not connected just lined up, you can push and see space where the coolant comes out.

It is odd that it would start right after changing the tank if the tank were not the issue but it looks fine. I think we may have just moved it a little more when we were in there or something but i DONT SEE ANYTHING HOLDING THE COOLANT HOSES TO THE ATF HEAT BOX. Are there supposed to be clamps or something, if so can I buy them or do I have to replace the whole box for $250-$300?

Below is a picture of an ATF box, also I found a clip (literally just hanging out down there) and put it back in (like in the pic. by the green arrow) thinking that was the problem but it was not,...sadly. I am going to have to sell if I can't figure this out myself, I cant afford to take it to the 1 MECHANIC IN TOWN WHO WORKS ON THEM every time something comes up.

_a2_

 

[Salzar]

I replaced my expansion tank and A/T thermostat because I was told I was leaking from the bottom fitting, it looked fine but I replaced it anyway. First drive over 1 block and coolant exploded everywhere, Looking underneat it seems to be coming from the heat exchange box where the coolant tubes connect to it. The don't even look connected just lined up with the holes. Can it be possible that I just replaced my A/T thermostat with a faulty one or something like that or should there be something holding those coolant tubes to the ATF box?

 

[tim330i]

Welcome to Bimmerfest! Is this issue on your 04 X3?

Tim

 

[kakarotyaaj]

Dude I just finished replacing my original radiator had to removed the heat exchanger out to pull out the radiator and I replace the oring on the heat exchanger as well.
There are 2 Oring on the heat exchanger you need to replace those 2 oring it could be bad.
The middle one don't have oring it is held by the snap in clip that you are referring too.
I got the oring at NAPA very cheap and its very easy to replace.

Link is below: #13 is the oring
http://www.realoem.com/bmw/enUS/showparts?id=PA93-USA---E83-BMW-X3 3.0i&diagId=17_0307

NAPA part# ATM 17111711987
https://www.napaonline.com/napa/en/...711987&isApplication=true&productReferer=true

 

[Salzar]

I can try that but it looks dry up around the tank, its down by the ATF heat box that is wet and i don't think you should be able to wiggle it and mine does. Looking at pics it is just held on by one clip and this does not make any sense to me?

 

[Salzar]

**** I see you mean the two orings in the box not the tank. I was thinking that I will give it a shot. Could you change them out from below the car or will i have to remove tank again and go from top?

 

[kakarotyaaj]

**** I see you mean the two orings in the box not the tank. I was thinking that I will give it a shot. Could you change them out from below the car or will i have to remove tank again and go from top?

Yes, you need to remove the Engine encapsulation plastic cover under to gain access that is how I change mine.
After you replace the oring and put it back make sure the heat exchanger flush with the expansion tank holder.
You won't be able to wiggle it out without a little force if you do then it is not seat in correctly.
Good luck let me know how it goes.