I have the same problem with mine it's an 57 109 crafter, smokes only when warm/hot. But it seems to be more blue than just white! Only happened at a junction or stoping at roundabout, stop then pull away! Bought mine like it . The two pipes coming off the dpf where blocked off and where they go into was linking together! Not sure why? Any help would be great?

You can smell a slight smell off oil burning again only when warm / hot?

Thanks matthew