[white944cup]

I'm doing similar things to my 88 Turbo right now. So far, every rubber seal and o-ring I have removed is flattened out, hard, and leaking. Check the rear end caps on the balance shaft housings. They look like freeze plugs. If the caps are loose, then the rubber o-ring has shrunk and oil is leaking down the rear of the block. My lower one is loose and leaking, so I am doing that one. My suspicion is the lower one sees more heat because of the proximity of the exhaust manifolds. The upper one is OK, so I'm not messing with it. The turbo has to come off to get to that one, and I'm not going there right now. Also check the oil line going into the top of the turbo. There is an o-ring that fits in a groove in the underside of the oil line flange. Lots of heat there, and the o-ring was flattened out and there are signs it was leaking oil onto the forward side of the turbo housing. Good luck!