Ok so on my 99 323i I replaced the expansion tank several months ago, a short while after that my coolant light would come on and off randomly while driving, it would stay on for 10 minutes or so then just go off for a couple minutes then go back on. my engine temperature never rose above normal and i would just put coolant in it once a week until now when im finally getting around to fixing it. The coolant in my expansion tank would go down but not drastically, i could see signs that coolant was spewing from the upper hose connection area with the radiator, yesterday i replaced the upper hose but on my way to work today the coolant light came on again, looks like its coming from the radiator side of the connection, any chance you can replace that part of the radiator or is it all one system? how hard is a radiator to install? any help would be greatly appreciated!