Not-specific-to-MB considerations would include lash adjusters (sometimes called lifters) that need cleaning (dirty lash adjusters can 'tick' when the engine's cold) an off brand oil filter (that doesn't allow full pressure to the chain quickly enough).

I haven't looked into an M104 or even my M103 to see how the hydraulic lash adjusters work on these cars. But anything that can trap oil can accumulate sludge over time.

Sixto
91 300SE