hi friends,
I'm new here, and i from Portugal.

I have a Fiat Punto 1.2 75 HSD 1994, and i have a strange problem.
The problem is:

I start the car, and didn't smoke of exhaust,
pass a few minutes i accelarete and start smoke (white smoke i think)!

the strange thing is that the car is not losing oil or water.

what could it have been ?

someone can help me?

:idea:

do compression test

could be condensation that has collected in the exhaust system, burning off as the exhaust warms up. this is common in cold weather, but I see you're in Portugal so it's probably not that cold!
does the problem continue after a long drive/when the engine is nice and hot?

as above.. there is a puff of white smoke that clears or once warm its constantly putting white smoke out?