Hi, I have a 03 Jetta TDI. I realize that some smoke is normal but on cold starts, the car runs rough and smokes more than normal. I am thinking that the valve seals might be worn because if the car sits too long, oil drips into the cylinder, and causes smoke. However, the car only has 120,000 miles, so I would not have expected the engine to be worn so early. Once it's warm it runs better and if it's started when warm, very little smoke. Is this the valve seals? Any ideas? I've heard that burning oil is blue, but how blue is blue smoke? The smoke I am getting is not blue like the sky, but I can tell that it's not white like burning coolant either. I'm nots sure if it's black because how dark is black smoke?