Hi, I have a B7 S4 55 plate 134k miles. I get black smoke coming out of the exhaust when I accelerate. This doesn't happen all the time. It seems to happen if Ive just come off the motorway come to a stop and then pull away. I can see the tail pipes drivers side look fairly black covered in soot. Also I can smell Oil when the car is just idling. I'm using castrol 5-40. Anything obvious I could check to get any ideas of the fault. If any?