Help! Previa, Lots Of Smoke...

[MarkL]

Any advice welcome -

2002 Previa GLS Diesel 2L, ~85k miles. Driving along a dual-carriageway on Monday something in the driving mirror caught my attention. Looking, all I could see behind was thick, white smoke. Lots of it, covering the entire three lanes. I pulled into a lay-by after about two minutes. Cars following had slowed down and had headlights on. Thinking my car was on fire I legged it into the adjacent field. Well it wasn't fire so I waited five minutes and started it up. Same thing, lots of thick white smoke pouring from the exhaust, very acrid smell/taste. Called the AA, who came after 45 mins or so. And he could find nothing wrong - it wouldn't smoke, levels were fine, no warning lights - nothing. Engine was fine, no loss of compression or missing, no oil in water or vice versa. He followed me to the local Toyota dealer. I left the car there, collected it today. They could find nothing wrong. Complete mystery.

Anybody have any ideas/similar experiences?

Mark