Porosity in the rear of the engine block can cause oil leakage around the rear engine cover. Porosity may be found at rear of the engine and the repair procedure in the service bulletin describes using RTV silicone sealant to fill the porosity. There is also an updated rear engine cover for when porosity is found on the gasket mating surface.Google+
Car Problem Reports
Saab 9-7x Engine Oil Leak at Rear Engine Cover Area
Saab 9-7x Problem
Engines Affected: 4.2L 6 Cylinder, 5.3L V8, 6.0L V8
Visitor, 2009 Saab 9-7x, 4.2L 6 Cylinder, 156,000 mi
Had leakage in the rear part of the radiator to the power fluid hose.the piece that connected them together was rotted.