cylinder head nuts every 50 hours.
That entails taking all the valve gear off. Say 3 hours for an experienced diesel mechanic, cost of new gasket and a cou;e of oil pipe seals.
The instructions for removing injectors do not work. The engine is built differntly from the manual.
When I see that kind of nonsense in a manual I question who wrote it. The ofice boy? the janitor?
Hence my lack of respect for Volvo advice