One for the mechanics.

[Polar Bear]

My old Kontiki 2.5td did this for at least ten years and nobody ever got to the bottom of it. New Glow plugs once fixed it but it didn't last long. Then they suggested it was the injectors. They were fixed and it improved a bit but returned to form eventually. In the end I just left it. It would be a bit lumpy in the end on start up as well as kicking out smoke. Like yours as soon as you drove it up the road it was fine and stayed fine until you left it overnight and started it again the next day. I ran it like that for years and tens of thousands of miles. Every time I started it the ice cap lost another metre and a dozen polar bears died.

Oi! you leave my relatives alone. The van may be over-fueling on start up. Check if the oil is contaminated with diesel.

 

[Marty]

I have a similar thing but only if I put my foot down in 4th going into 5th it never smokes any other time. 2.8 peugeot 100,000 miles.

 

[KATBIT]

It's probably the valve stem seals are getting old and hard.
As its been mentioned you could try the stop smoke, but it will be a temporary job.

Depending on what base vehicle you have.

You could live with it and wait till it gets worse or get the head serviced.

A decent mechanic will be able to do a diagnostic for little money and then you can make your own decision.

The only major factor is the smoke test with the MOT .

She mite fail if there's visual blue smoke at yhe time.