Loud Engine Noise problems of the 1999 Jeep Laredo

I was driving on the highway and all of a sudden I herd a loud noise and before I knew it my truck was filled with smoke and I couldnt see out the wind shield I had to hurry up and get to the side by the guard rail while struggling to see, and I had my kids in the car with me . I had to have it towed to my house my mechanic came to check it and discovered a big hole and when he took the engine out he said you could tell it was there already and the dealership had to patch it up before they sold it to me because it was to perfect and I only had the truck for 1 year.