I have a 2000 Grand Prix 3.8L and I noticed my car has oil running down the passenger side of the engine and it appears to be trickling out of a threaded hole on the side of my engine. The hole is just below the lower intake gasket but above the water pump. I found the below picture online of the side of a 3.8L engine and there appears to be a bolt (marked with yellow arrow) but my car is missing this bolt and just has an empty hole. My question is what is this bolt? Does it go to anything inside the engine? Do I need a certain length or can I just pick up a short bolt at the hardware store that matches the threading to screw in a stop the oil that's trickling out?