Oil spitting M225ti

[Ringhals]

Perkins M225ti spitted out approx 1-2 liters of engine oil the other day! Lots of cleaning to do but why? Haven’t done it since then. First thought was too much since the change last autumn and it just got rid of the surplus. Seems reasonable but after clean up I had to fill 1,5 l to come up to lowest marking on the deep stick. Why spitting out that much? Hard to tell where it came from but it was a mess on both sides on the engine so the crank house ventilation that ends where the air intake is seems likely. Now 6-7 hours running as normal. Any ideas of possible scenarios?