2010 Ford Fusion - leak persisted after new valve cover

Replaced the valve cover gasket and used a sealer around portion of cover that didn’t have gasket. Still have oil leak even after further tightening. Any ideas?

What engine? Can you see the leak path so you KNOW it is the valve cover?

It’s a 4 cylinder and the leaking is on the passenger side, near the top and on firewall side. Car has 115k. Thought it maybe blow by from internal pressure. Engine still has good power. Thanks for help. Greg

Is the mating surface of the cover perfectly flat? The way to tell is to place it on a known flat surface. If it was ever overtightened, it may be distorted near the bolt holes. The correct torque is usually lower than people expect. Sometimes careful hammering can get it back into good enough shape.

Here is a pretty comrehensive video doing the valve cover gasket job. Notice there is no place on the cover that didn’t have a gasket. Take a look and see if you missed anything. So in what location did you use sealer instead of a gasket?