Thanx for all the responses...

Yes, I changed the hoses too. And my trip to work is about 20 km each way, so even in -15 C that day, it warmed up a fair bit.

I'm starting to think I put the hoses back wrong. Does the top one on the separator connect to the valve cover? Other then that, maybe there's just a lot of moisture still in there from before?

I lost about 2 litres of oil that day and the whole underbody, including the rear mufflers, was COVERED in oil! Seems to have no leaks now when starting in the garage though.

I think I might just top it off again and keep driving it.