488 engine problems, need help!

I think you mean you have oil and antifreeze mixed? How do you know you have them mixed? Seeing it on the dipstick or just assuming from the smoking engine?

If the 488 uses the same kind of engine cooler like prior Ferraris the mixing could be from the cooler, however I would be surprised if that was actually the culprit. When did you replace the turbo? How many miles since and how quickly did the symptoms you're describing happen within?

 

check for pressure coming in to the radiator itself rather than the overflow bottle.

 

Does it mix without the engine even running? I shudder at the thought of running an engine with water in the oil. I had to do a rebuild on a Mustang V8 many years ago due to a gasket failure and the resulting scoring of bearings.

 

I haven't been under the lid of a 488 myself, but do the turbos get coolant, or only oil? Typically you'd expect the last thing you touched to be the problem
The next easiest thing to check is the oil cooler(s), assuming it's water-to-oil... you can pressure test both loops for a leak.
For that matter you can usually pressure test the coolant loop on any engine as a start.
I have a sinking feeling that the turbo failure caused damage downstream in the intake tract (if it's anything like the American V8's I've worked on in the past there are one or more cast parts where oil and water are neighbors) or in the oil system, where small bits of turbo debris could have circulated to the oil cooler and punctured the thin tubing.