I would say its the lower intake gasket which is about 7 hours labor and 200 in parts and fluids
Bulletin No.: 03-06-01-010C
Date: April 08, 2008
with 3.1L or 3.4L V-6 Engine (VINs J, E - RPOs LG8, LA1)
This bulletin is being revised to update the Parts Information and add an Important statement. Please discard Corporate Bulletin Number 03-06-01-010B (Section 06 - Engine).
Some owners may comment on an apparent oil or coolant leak. Additionally the comments may range from spots on the driveway to having to add fluids.
Lower Intake manifold may be leaking allowing coolant oil or both to leak from the engine.
Install a new design lower intake manifold gasket. The material used in the gasket has been changed in order to improve the sealing qualities of the gasket. When replacing the gasket the lower intake manifold bolts must also be replaced and torqued in sequence to a specification.
Diagonal bolts may require a crows foot to tighten.
For vehicles repaired under warranty, use the table.