I drove 65000 miles ,change the oil more than 10 times and 2 of them had the oil over the max level(half a litre).
it happened after the oil was changed and the oil counter on ecu was not reseted. if the oil is changed and the the counter not reseted it will block the dpf regen when oil quality gets to near 80% degradation, as soon as it gets to 100% the sign change oil will come up, as I understood each oil change is programed to reach 100% degradation according to an algorithm when reaching 18000km.If I do an oil change after counter in ecu marks 12000 , altough
it has new oil it assumes the oil is at a high level of degration a stops the regen.
I normaly drive under 2000 rpm for more than 1000 miles, so the car is not doing any regen and worst ,it pauses a lot of regens each time I go over and again under 2000rpm. Alfa Dealer told me if that happens a lot of times or if it cancels dpf regens than it is usual that diesel gets in oil, not only with 1.9jtm but also the fiat 1.3 jtdm.
I never had any problem since I started to change oil each 8000 , clear the ecu oil counter, and do a forced regen each 800 km using FiatECUscan.First time i noticed the problem I changed the oil and filled only with 4 litres . THe counter didn t reach max , but after 5000 km it was marking oil max . I do not know what engine part is leaking oil into engine but alfa dealer told me it happens not only to me me but to a lot of jtdm engines,
and nothing is broken. I hope I am explaining everything the way alfa dealer explained to me.
We do have a LOT of fiats alfas jtdm here.