my recently purchased 2007 320d se tourer runs fine. but in the morning, on first start-up, their is an initial miss fire,smoke and a clunking sound. this lasts for only a few seconds,
Perhaps a injector is leaking. Maybe coolant leaking into a cylinder over night.
Get a code scanner to make sure, but my money is on a failing glow plug. This won't cause a EML to light up but wil cause the symptoms you describe. Initially one or more of the cylinders won't fire correctly until it gets hot enough to ignite the mixture in it, which will causes the smoke and misfire.
Search BMW 3 Series Questions
BMW 3 Series Experts