Water leak

[teammccrory]

I have a 2006 X3 D MSport with a mysterious water leak.  As I pour water in at the front, it runs out at the back! Seems to start somewhere below the filter which runs across the bulkhead.  Took this off but no joy.  Looked up from the ground. Cans see a trickle dripping onto the gearbox but not the source.

Anyone any ideas where this might be coming from, please?  Car runs fine, no overheating - just needs topped up every 5 minutes!  Really annoying.

Thanks in advance.

[X5Sport]

Front and back of what?  Coolant, washer fluid or?  Pouring it in where?

[teammccrory]

Sorry - coolant into expansion tank, runs out at back of engine - somewhere - and drips down over gearbox.

Thanks

[notyalc]

You might want to look at the level sensor in the bottom of the expansion tank. When it fails the coolant drips into a trough in the chassis rail and then runs rearward.
New expansion tank required I think as the sensor is part of the tank.
That’s my experience anyway, but on a 3.0 L 2012, yours may be different....

[MattX]

Here's a diagram of all the cooling system parts.

Check each one!

http://static.bmwfans.info/images/epc/NDQ4ODRfcA==.png

You might get a better response if this was in the right X3 subforum btw, more people with this year might have had this issue in the E83 section