re:2002 duramax 2500HD 4X4 crew cab LB

Last week I developed a radiator hose leak on the bottom hose....only had to add water once....just a split at the clamp...cut 1/2" off, clamped it back on, good to go....did that on Sunday evening....Monday, I noticed oil dripping out of the crankcase vent tube on the front of the engine on the passenger side and oil has blown out everwhere underneath and rear of truck..about a pint mabey...this truck has never leaked a drop of oil...as of today truck still reads no oil loss on stick but it is still leaking plenty...any ideas before I take it in to the dealer?...could I have knocked something loose that I am missing visually?....there is also a little bit of roughness at idle...the truck has 82000 mi. & gauges are reading normal...bad injector?? thanks, Boots