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Old 01-11-2013, 10:39 PM
awdrev awdrev is offline
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Location: Maryland
Join Date: Dec 2012
Posts: 82
Mein Auto: 2004 BMW X3 3.0 Auto Tran
New OEM Coolant Expansion tank leaking? Could it be?! [UPDATE - Not fixed (UGH)]

So one of the first things I did when I got my 04 X3 is to replace the coolant expansion tank because the car was leaking coolant.

Well, it turns out that the leak was actually coming from the TOP RADIATOR hose (which I obv replaced) so, technically speaking, I didn't have to replace the coolant tank but I am glad that I did given that it had over 8 years of use. From what I can gather, the tank has been there since 2004.

Now, when I topped off the expansion tank, I noticed that it continued to leak. I left it alone because the car was hot and I didn't want to deal with it since it was a good amount...

Then I kept checking and the amount leaked has significantly reduced but it continues to do so.

Here's the situation: From what I can see, it seems there a small residue of engine coolant RIGHT AT THE TOP OF THE TANK... I am starting to believe that either this new tank is defective, or it could be the hose connection to the radiator that is leaking... just as a reference, this IS the top radiator hose that connects to both the coolant tank AND the radiator

As I said, the coolant tank was purchased from a BMW dealer... any thoughts or past experiences?

Thanks again

Last edited by awdrev; 02-02-2013 at 01:01 PM.
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