Coolant expansion tank

[omgboost]

Mine started leaking so I ordered a new one. I got it in the mail today and when I took it out of the box to inspect it, it sound like there is something loose in the tank that makes noise when I shake the tank. Is this normal?

[yco]

as far as i see its quite frequent thing among X BMW's..
not sure but i feel like it ll prevent it, i open the cap once or twice a month after parking the car to release the pressure when its not super hot..

[omgboost]

So the shaking noise is normal. I changed it out yesterday and it looks like the coolant stopped leaking. It is a common issue for all engines that use the plastic expansion tanks, not just the X. I've seen many 1, 3, 5 series folks have theirs crack. I also read somewhere that if you open your tank while hot, air can get into the system and you will have to bleed it. Inconvenient, yes but you know the tank will crack in 6 years so just replace it then.

[rodnex]

The shaking is normal. It's the floater (for the level sensor).

[Jennorm]

I'm looking for help with my 08 x3 expansion tank. I've replaced everything but still have a leak where the water pipe goes into the expansion tank. Is there supposed to be an o-ring between the two parts?

[omgboost]

Originally Posted by Jennorm

I'm looking for help with my 08 x3 expansion tank. I've replaced everything but still have a leak where the water pipe goes into the expansion tank. Is there supposed to be an o-ring between the two parts?

Can't remember. I know there's a metal c clip on the hoses. The hoses itself may be going bad.

[cgalan39]

it is O-ring on the hose that connect the tank to the hose, I'm just fix that problem on my x5
after expend $150 on parts a .99 cents o-ring fix the problem!