On the 3.9L V6 and 5.2L V8 it is often misdiagnosed as a leaking oil filter gasket, the oil filter adapter can seep from between the adapter and engine block.Google+
Car Problem Reports
Jeep Grand Cherokee Oil filter adapter may seep oil between adapter and engine block
Jeep Grand Cherokee Problem
Engines Affected: 4.0L 6 Cylinder, 5.2L V8
Average Mileage: 220,250 mi (195,000 mi - 275,000 mi)
Visitor, 1996 Jeep Grand Cherokee, 4.0L 6 Cylinder, 196,000 mi
Oil leak. Though it was oil pan gasket. Cleaned area found oil coming from above oil pan. Started engine and saw drip starting from oil filter adpter.
Visitor, 1995 Jeep Grand Cherokee, 4.0L 6 Cylinder, 195,000 mi
I have replaced this 3 times. I'm working with the dealership to a better conclusion.
Visitor, 1995 Jeep Grand Cherokee, 4.0L 6 Cylinder, 275,000 mi
Common place for oil leak. Cheap rubber oring. Bolt is in difficult place.
Visitor, 1995 Jeep Grand Cherokee, 4.0L 6 Cylinder, 215,000 mi
Have yet to repair. Major problem getting bolt broken lose to replace seals.