Low compression/ broken ring lands
I'm working on a 1998 2.5L. I bought the truck with a miss in it. After checking it out I found number two cylinder had low compression (60PSI) and the oil pan had a hole in it from rubbing the cross member, I assume it had a bad motor mount at one time. I pressurized the cylinder and only had air blowing out the crankcase. After I tore it down I can't see any problem with number two other then the piston being varnished up (as were all of them). If the rings were sticking they were not when I pulled the piston out. There was no indication of a bad head gasket and the compression came up when I put a few squirts of oil in the cylinder. The bore and pistons do not show wear and are still in specs. I also found the ring lands broken off almost half way around on number four piston. Did my compression gauge decide to fart at a bad time? What would cause the lands to break off between the rings?