grey smoke would tend to be engine oil rather than unburnt diesel,so is the engine oil level to high or is the turbo leaking oil into the inlet manifold,remove the turbo pipe large rubber type secured with jubilee clips,and see if it is sodden with oil.
glensmith
October 2008
I can answer this question...
my peugeot 407 diesel is blowin light grey smoke what can the problem be ?