This problem actually originated at the beginning of winter, but I got busy and shelved it till now. 2 of the 3 bolts on the centre of the valve cover would turn, but they won’t wind themselves out of the holes. I was told to grind the bolt heads down so that I can get the valve cover back off, and then work the bolts loose. But I still can’t get the “remains” of those 2 bolts to come off. I really don’t want to resort to cutting off the rest of the protruding studs and drilling it.
Any advice?