I humbly dissagree BigJim. In my opinion, if it were one or the other, that is, crack or gasket, I'd put the odds at 50/50. Still if I were going to bet on it, I'd go with gasket, simply because I've seen far more leaking gaskets than cracked heads. IF there were signs of water in cylinders, still 50/50. Several times I have seen head gaskets that leaked compression/combustion gasses into the cooling system without any such signs. jeepfun4u2, it's not unusual to have a one-way leak. The gasket or crack may only leak when the cylinder is actually firing with no loss of compression until then. so the engine would run normally (except for the temp fluctuations and percolation effects) with no sign of water in cyls or exahust.