There is no usual or unusual for the intake and or gaskets on this 3.8 L engine.
I think that is the eng. that is in this car, 4 years since the repair, that would be around 2008 so
that means you only got 1 MORE year out of the FACTORY gaskets! Gaskets have been improved since that
replacement was done. Have intake manifold checked and new gaskets installed IF that is where the leak is! Also dont put DexCool back in it, use the good old green stuff. That is better anyway i have found!
Have the installer check bolt torque after a couple of weeks of driving. Now, water in oil /external leak? Or vacuum leak.