I have a 98 montecarlo, 3.1 liter with 85k miles on it. The car has been sitting for 2 weeks, and when I returned to the parkinglot there is an oil spot the size of a quarter under the car. The spot was located under the oilpan area. Looking under the hood, there is no oil residue up near the valve covers, or around the cap. I have had the upper intake gaskets replaced about 30k miles ago, and had two questions: What is the likelyhood those gaskets are bad again, or where else to look for the drip? Any help would be appreciated.