Moving to Alaska with my Toyota I purchased a 'block heater' which is an inexpensive immersion heater for your engine block. To get it in you must first remove a pressed sheet metal cylinder out of your engine block. "Out" I said? Yes, you have to take a piece of metal, or a chisel that you can hammer, and put it to ONE SIDE of the plug so that when you bang on it, the plug PIVOTS in its installed hole, in which case you get a vicegrips on it and pull it out. This worked great in 1985. Fifteen years later, when I bought the Toyota pickup of my dreams and tried to do the same operation a second time on an engine of the same basic design, the plug simply went INTO the engine block! I was fit to be tied. I didn't think there was anything down there but the oil pan, but I could imagine SOMEthing chewing up metal and circulating it through the cooling system. Anyhow, I observed that the lost plug was still in view, and I was able to get a long-nose vice grips on it, and over the course of a couple of hours, with some cassette mix-types for inspiration and a bit of desperation I was able to wrestle the damn thing out.