Review on ACDelco 12607947 Professional Engine Adapter by Marcus Barlow

If you have a GM 3.5 v6 and you have a mysterious oil leak above the oil filter area, remove the filter and the actual oil filter adapter. The oil filter bracket is bolted to the block and has threads to which the oil filter attaches. That silly little seal bursts and then leaks. It is located behind the oil filter bracket adapter and is not visible until you remove the bracket. You will most likely find that the center of the gasket has come loose at one of the triangle's attachment points. This causes a fairly serious oil leak while the engine is running. I don't know if this fits other GM v6 engines but I suspect they have a similar setup. There are several YouTube videos that walk you through this repair. I thought the filter itself was leaking and after changing the filter I finally found out where the leak was coming from. Much luck!