If you were using a significant amount of oil, then I would think the valve guides would be suspect.

However, yours sounds like a fuel/incomplete combustion problem. If you saw a significant amount of carbon on the nozzle itself (as mentioned in your other post) then there could be problems with the prechambers which have small holes to pass the atomized fuel. Carboned prechambers could also affect glow plug operation.

With that much coking and carbon, has this car been run on waste veg-oil?

__________________
Sam

84 300SD 350K+ miles ( Blue Belle )