Diesel Carbon Build up??? Help

[X-ray Lima]

That sounds suspiciously like one of two things to me.

A blown head gasket can smoke constantly, dependent on where the blow out is, but is not usually too heavy.....

Blown turbo seals generally smoke heavily and pretty much constantly!!!

[toolman68]

have checked oil and coolant and neither show any signs of having mixed.

Where can I get hold of an exploded view diagram of the engine?
Or for that matter, the whole car?

Thanks for yr help