Hi ! Here's the story: , bought this excellent -90 735iA ( 180' km ) in september 2000. Found out the hard way, by boiling motor, that the car had an water leak.My first thoughts was that cyl. head gasket was gone.Put it in to several "so-called" BMW experts, but ended up to be leak in circ.pump / heater reg. valves. Changed same & still leaking. Into garage again, and found leak in "Webasto heater", -& car is still leaking. Has pressure tested cooling system , and found it OK. The leak is minor ( 1/2 l / 200 km ). Can't see any outside leaks now... Any ideas?