i have a 2002 bmw 530d sport touring e39 the car has been suffering loosing power at motorway speeds i had the crank case valve and breather changed this sorted the problem for 2000 miles the the problem came back and has used 2 litres of oil in 2000 miles it doesnt appear to smoke no head gasket problems no smoke from the oil dip stick. car only has 77,000 miles on it the garage ran a engine computer on it and it came up with a pressure problem? they then said the engines loosing pressure, or the turbo could be burning of the oil pls help thanks steve i dont wanna put the car i to bmw if i can help it! or do i sell it as it drives relatively fine up to 80 mph