a diesel engine does not require maintenance like a baby, its a pretty tough engine - It only becomes problematic when ustaadjee mechanic thinks he can outsmart the manufacturers
ustaadjee mechanic has no idea how to diagnose a diesel engine fault, e.g. ask a diesel ustaad what is the remedy of intake backwash in a toyota 2C diesel used by Indus motors, and why after a year or two the idle speed control system does not work correctly on it.
A correct running diesel would be considered "broken in" after 150,000 kms, I just recently did a compression test on my mercedes benz diesel here, its done 110,000 miles (176,000 kms) and each cylinder showed 480 psi compression, new engine compression is 500 psi, not bad huh..
Maintenance done was coolant change recently, All 3 fuel filters changed recently, oil changed with mineral oil every 4000 miles.
IMO the engine has just started its working life and it pulls sweet though its rev range. The most weird part is that some mechanics here had condemned this engine "DEAD" because it refused to start at all. The problem was a blocked cat convertor that was causing high pressure in the crankcase causing the injection pump self shutoff to activate.