After I rebuilt my 83 240D Diesel, I noticed about every 1200-1800 miles, I would lose 1/2 a quart of oil. A pro told me it was because I should have rebored vice simply replacing rings--however I notice a line running to the Fuel Injection Pump, and I'm wondering if its natural for oil to be fed to the injection pump--I dont think there's a return line so perhaps the oil is intentionally consumable. Do you know if some oil should be lost, and that my loss is normal?