Ford 2003 Mustang Workshop Manual page 1418

16. Inspect the valve cover spark plug hole gaskets. Install new gaskets, if necessary. Make sure
the gaskets are correctly seated on the valve cover.
17. NOTE: If the valve cover is not secured within four minutes, the sealant must be removed and
the sealing area cleaned with metal surface cleaner. Allow to dry until there is no sign of
wetness, or four minutes, whichever is longer. Failure to follow this procedure can result in
future oil leakage.
Apply a bead of silicone gasket and sealant in two places where indicated.
18. To install, reverse the removal procedure.
Tighten the valve cover in the sequence shown.