Originally Posted by Dackelone
First, you need to check the coolant level when the engine is COLD>! When you check the engine coolant when it is cold it will be at the MIN MARK.
So... the top of the"float dip stick" should be FLUSH or LEVEL with the top of the exp tank threads.
Don't think it is really that hard. There are two bubbles on the stick. When cold, if the top bubble is below the opening, top up. Just don't make the second bubble go higher than the opening when topping up. If when cold the level is somewhere between the top bubble and second bubble, the level is okay.
BMW has had it like this for a number of years now.