these old diesels always run black oil...after 5 minutes of running on fresh oil its black already. its not a big deal, if you run synthetic you can get 6000KM no problem out of the oil.

just look at how much industrial diesel engines (ie. generators, hydraulic pumps, whatever...) get used have a massive lack of maintenance. and they run forever.

my dad owns a service rig company and his light plants have 2.2L Isuzu diesel engines and they are poorly maintained but run for 50-60,000 hours problem free.

diesels are alot tougher than you think.