I have y2000, 4,4l and meter shows less than 70k miles, however I cannot say 100% sure if that is real deal or not.

Last time I checked under bonnet, there was something done (I believe heater wires added) to the oil separator vent hoses (no.4 & 5 here;http://www.realoem.com/bmw/diagrams/t/x/61.png), so that´s where I´ll look into first.

However, I would not like to remove whole intake manifold, if not necessary, so any tricks to check if there´s a gasket leak, without removing the manifold?