I just completed a LIMG (lower intake manifold gasket) chage on my 99 olds alero coupe, the car ran nicely before the change, now the car sounds like it has no compression on 5 cylinders, it never started, just hucked and farted like it wanted to, and keeps making loud pops out of the intake, followed by exhaust smoke, and normal exhaust smell, the pushrods are in the correct orders, and the gasket is in correctly, now, when i put the rockers on, they depress the valves slightly, and 2 depress all the way down, why is this? (this is on one side btw) but the opposite side does the same thing, two depress all the way down, and the rest depress slightly, why is this and what do i do to correct it?