Just bought an 87 760 w/mitsu turbo. It is leaking oil from a hole in the casting that fits between the exhaust manifold, the exhaust pipe, and the turbo. It is also leaking oil into the exhaust for lots of blue smoke--uses about 1 qt/500 mi. Have ruled out excessive crankcase pressure. I'm assuming some seals in turbo leaking from oil cooler part? The turbo works good and has no play in the rotating part. Can seals be replaced w/o messing with the bearings? Where can I find an exploded view of a mitsubishi turbo? any and all ideas appreciated