Coolant Reservoir?
 

Well I've been getting "Low Coolant Level" warning on and I've been adding coolant here and there and I realize that my coolant reservoir is leaking. The main reservoir's body is in 2 pieces and there should be a gasket between them. I think the gasket leaks. I went on RealOem and looked at this diagram, it does not show a gasket.

Am I wrong about it having a gasket inbetween the 2 pieces or they don't sell that seperately but instead of a whole part. But I don't see the part number for the reservoir.

Does anybody know?
Thanks for any inputs.

Here is the piece I am talking about circled in gray.

http://i53.photobucket.com/albums/g57/engz/239.png

20 EXPANSION TANK 1 17107514964 $79.43

I have already replaced mine since it was leaking as well...make sure your hoses aren't the fault tho...if you haven't replaced those yet u might have to.

RealOEM.com BMW E53 X5 4.4i RADIATOR/EXPANSION TANK/FRAME

Cool thank you so much :thumbup:. And good advice with the hoses. I will probably be changing the hoses also because I need to flush out the coolant. I think the owner before this had a different type of coolant and I wouldn't know if it is free phosphate. So maybe after these awful rain days in NYC, I'll find hours to bang out the work.

It is indeed one part . Two plastic parts sealed together. you have to replace the entire unit. Just ordered mine this morning. carefull removing the clips on the hoses they are fragile.

I just replaced the reservoir on my wifes 05 4.8is. It was leaking somewhere from the bottom near the sensor. Easy install though. Two bolts, hoses, and clamps.....wala! No more low coolant light!