I have tried to remove the OCV from the car but it will not come out of the block. I have removed the wire and retainig bolt. I can rotate the ocv and pull it out only far enough to get a thin screwdriver blade between it and the block. It feel as if there is something inside the block keeping the OCV from comming out. It is loose. I can move it in and out, but only very slightly. Is there some kind of retaining clip inside the valve/head cover causing this?