We have a 2003 Cavalier with a 2.2L Ecotech engine. It had jumped time and sheared off the teeth on the exhaust sprocket where it goes onto the camshaft. The camshaft on the exhaust side has rocker arms. On one of the rocker arms you can remove it. There is no pressure on it at all and the one next to it is a little loose. We bought 2 new ones and replaced them and they are still just as loose. Camshaft looks good too. What could be causing this?