changing the coolant shouldnt have anything to do with a leak,
dont use any caustic flush addatives and simply drain, flush with water and refill with new antifreeze and diastilled water. I would flush with water a couple times though since your probably not going to remove the drivers side block plug. Drain, close it back up fill withe water, run for a few, drain, close up fill run, drain then do the new fluids. Figure out the capacity first and add half that amount of antifreeze first before the distilled water incase there is still water in the block. No secrets here as to bleeding as in the 6 cyls.
95 E34 530I V2.37
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