The AERA Technical Committee offers the following information regarding broken exhaust manifold bolts on 1999-2005 Ford 5.4L VIN L engines. This information applies to non-supercharged Ford truck engines. Generally, this condition is first noticed because of excessive exhaust noise that is the result of a manifold leak.
This engine is used in the following vehicles: Ford: 1997-2004 Expedition and F-150; 1999-2004 F-Super Duty; 1999-2005 E-Series; and Lincoln: 1998-’99 Navigator.
To reduce the likelihood of subsequent failure after repair, Ford now offers a stainless-steel stud and nut for these applications. The stud is available as P/N W703902-S403 and the nut is available as P/N W701706-S2. The supercharged versions of this engine have not exhibited stud or nut failure, however, the new parts could be used for those applications as an upgrade.
Any time these repairs are made, the exhaust manifold gasket(s) must also be replaced for an effective repair. To install the components, torque the studs in the cylinder head to 71-115 in.-lbs. (8-13 Nm) and torque the nuts on studs to 204-239 in.-lbs. (23-27 Nm).
