Not come off of a Ford (Renault 21 turbo) but a turbos a turbo (T3?) car seems to smoke on over run, and when pootling about - white smoke - under load seems to be fine, and will clear if revved for a bit, but if changing down gear to slow for a 30 or traffic plooms a bit.

We took the turbo off, nearly half the oil feed pipe gasket had been covered in sealant so not sure if has had slight oil starvation (this turbo was fitted 6 months ago (second hand I assume)) quite a bit of play in the shaft, looks wet (unlike dry/sooty) and feels oiley, so could it be turbo to blame for smoke?