I have a 2004 5.9 Ram 2500 diesel and it was losing power and i change the fuel filter but went i remove the old one i see oil on it i could understand why but i put the new one in it work perfect for half day and the same problem start all over again oil in the fuel filter and i`m going crazy trying ti fix it and i just can can any body help me please i want take the tank out to clean it but i dont now if i m doing the right thing plase help.