sounds like it could be the gasket.... heres a quick test to tell if its a lower intake manifold gasket... take your oil cap off... take your finger and rub the inside of the valve cover.... if the oil on your finger looks like pudding.... trust me it will if the gaskets bad... i had gallons of the stuff in the motor when i did the gasket in my grand am... itll be thick and milky....its from the oil absorbing the water from the coolant...