I changed the intake gaskets top and bottom along with valve cover gaskets on my Ford F-150. After I finished it was hard getting started but I finally got it started and now it sounds like the valves are knocking. I changed the oil, but they still sound like they're knocking. Do you have any ideas what could be wrong?
I'm not sure how the F-150 is setup but if you had to remove the injectors to remove the valve cover or intake, check that the injector seals are still on and the injectors are down tight, or this can create a knock.
You've either got the valve covers on the wrong side or it's turned around backwards.
What year Ford is it? If you did not loosen or take off any of the rockers about the only thing it could be, unless something fell in, would be the valve covers on wrong. As to the hard starting it may be a vacuum issue. With the engine running spray some carb cleaner around the fittings and throttle body. If a change in rpm occurs there's the leak.