Smoke at Cold Start

I have a 02 Jetta TDI with 168K on it. The car is running find, I had the EGR cleaned up, and I am taking good car of it, but I notice few month ago that I got smoke at cold start in every condition. The temperature can be -25 C (-13F) to 30 C (86F) and even during a hot summer day I am getting smoke. It look more like a blue smoke. I had my car driven by a friend and I was following it, and there is no smoke during driven except under full exceleration. Anyone have an idea about what is the cause of that smoke?
Thanks

yes, it's a diesel.

Max, try doing the diesel purge with LubroMoly. Its a fairly simple task and may help.

All diesels will smoke at start. My 2000 has 280k and runs great, but will smoke for 15-30 seconds when cold . Good luck.