Welcome to the site. I just recently purchased a T4 myself. Same age as yours with almost the same mileage actually lol. Sadly I can't answer your question but hopefully somebody will be along soon with some help.

did you have any lights on the dash, how was it running before this prob?

Hello, sorry to tell you that you have probibly done a piston oil ring seal. Big job. cant say how much though. Bad luck fella. :(