I currently have antifreeze in my oil and I'm trying to isolate the cause. First thought was to remove the oil cooler and pressure test it before I concede it's the head gasket. Hopefully I'm correct in my thinking... My question is that I removed the oil cooler cover and gasket but the actual core seems like it doesn't want to come out. Are there any "hidden" bolts that need to be removed, or do I just need to gently separate it from the engine block? Any advice or tips would be greatly appreciated. Thanks in advance!