well this is my prob i was going down the interstate and my truck for some reason was running right. well when i get off the interstate it started knocking really bad. well i figured oh hell i have a rod knock but now it has subsided you know. well it goes off and on now everytime i get on the accelerator but it isn as bad as it was. Well, my dad thinks it is my rocker arms and something else. but any help would be appreciative i am not the most knowledgeble on trucks sorry guys.