Leaking antifreeze expansion tank or hose ?

[BMWX5CHI]

As title says, my X started leaking from which seems to be at the connection of the expansion tank on the bottom. (see attached picture) Now my question is, has anyone had theirs leak from there? and if so, what was the culprit? hose, tank or both ? Looking to fix this soon as I don't want my X just sitting in the garage leaking all over the place. It seems to only leak after I have taken it out for a drive. Won't leak if I let it idle. I can not purchase the single hose, I have to buy the entire set as it looks like it's all clamped together. Any help is truly appreciated.

[BMWX5CHI]

Well I went ahead and removed both the expansion tank and the complete hose. Might as well change both to avoid future problems. Removing the hose is a bitch , have to remove aux fan and unclamp the plastic connectors on the hoses. They are fairly easy, but since some of them are in hard to reach areas, it makes the job 100x harder.

[the_ulf]

the tank has a habit of cracking around a seam at the very bottom, it's a 5 minute swap. done it earlier this year.

[BMWX5CHI]

Originally Posted by the_ulf

the tank has a habit of cracking around a seam at the very bottom, it's a 5 minute swap. done it earlier this year.

I went ahead and ordered a new tank and the the complete hose pictured. When I jiggle the connection at the bottom, it starts to leak. Don't know which one failed, but its a good idea to replace both while i'm in there.

[Price]

Usually it's the tank - it develops a hairline crack, almost undetectable, yet causing leak. Replacing it is a good thing, as there's a built-in filter inside, so you get a bonus (sort of) with new part.

[bmrboi2]

Just Wait until your radiator shits the bed. Thats a fun job. Fairly straight forward but almost 3 hours and not a ton of fun when that stupid radiator fan shroud doesnt want to come loose.

[BMWX5CHI]

I'm not too worried about the radiator, I'm going to change it in the summer. Just finished putting everything back in and ran into some problems. Some of the coolant hoses broke off where the arrows are pointing too. I already got a solution for part number 13, which is the arrow on the right of the picture. I'm going to put in a brass tee and that will fix the problem there. No need to buy a new hose only to run into the same problem in a couple of years. The other nipple broke off right to the point where there is no fix, so I have to drive an hour out of the city to get the part.

[bmrboi2]

If Im not mistaken thats the hose that has been revised with the radiator revision. Damn I wish I'd have known sooner, you coulda come up and harvested what you needed off of my wrecked 08.

[BMWX5CHI]

Yeah, went to local BMW stealer and got revisioned parts. Just finished putting everything back together. Ran bleeding procedure and topped off the antifreeze. Now she's good as new.

[CLS70]

Originally Posted by BMWX5CHI

As title says, my X started leaking from which seems to be at the connection of the expansion tank on the bottom. (see attached picture) Now my question is, has anyone had theirs leak from there? and if so, what was the culprit? hose, tank or both ? Looking to fix this soon as I don't want my X just sitting in the garage leaking all over the place. It seems to only leak after I have taken it out for a drive. Won't leak if I let it idle. I can not purchase the single hose, I have to buy the entire set as it looks like it's all clamped together. Any help is truly appreciated.

Hi there - having EXACTLY the same issue - took me a bit to get the source of the coolant leak but this post helped me a lot - I cleaned up the area and then proceeded to wiggle the hose / connection under the tank, even with a small pressure/movement, it started leaking inmediatly (not drops, a constant flow) so I have ordered the Tank (for now as the hose was out of stock) so will see if that fixes the issue..............