An engine oil leak may develop from the rear of the engine. This is commonly caused by a failed oil pump drive o-ring seal. The leaking o-ring should be replaced to correct this concern.Google+
Car Problem Reports
Pontiac Grand Prix Oil Pump Drive O-ring May Leak Oil From Rear of Engine
Pontiac Grand Prix Problem
Engines Affected: 3.1L V6, 3.8L V6
Visitor, 1992 Pontiac Grand Prix, 3.1L V6, 90,000 mi
Had a leak for a month before I got it fixed. It was leaking from the rear of the engine. My mechanic said that it was a 22 cent o ring that goes on these vehicles a lot.