2008 X5 3.osi - I thought the leaking was from the expansion tank and I replaced it. The leaking was from the bottom of radiator and had to be replaced for $1100. Indy shop did work with OEM radiator. Had to replace the factory hose too. That included a throttle body. fuel injector cleaning.

While they were at it - I changed all spark plugs and now runs as good as new. 94K. Also just put new Pirelli Scorpion RF on all corners. Tire Rack had a special for under $180 a tire. Great deal in run flats, and the tires feel pretty good so far.

I now have an OEM expansion tank that is not cracked and I am looking to sell it.