There is a technical service bulletin for the V8 engines regarding a possible problem with the spark plug being ejected from the cylinder head, damaging the threads in the spark plug hole. If the vehicle is under warranty, cylinder head replacement is recommended. If the vehicle is out of warranty, Ford authorized the use of a specific thread insert to repair the head.
2003 Ford Excursion Problem Reports
RepairPal Verified 2003 Ford Excursion Problem Reports
The high pressure diesel fuel injection pump may fail, resulting in a "no start" condition.
When changing the fuel filter, if the fuel in the filter bowl looks gray or black, it may be a sign that the fuel injector O-rings are allowing high pressure oil to migrate into the fuel return system. Symptoms of this are rough idle or hard starting.
One or more of the door locks may become inoperative due to resistance in the circuit. In some cases, replacement of all actuators will be required to correct this issue.
Intermittent rough idle may be caused by the EGR sensor sticking, causing the EGR valve to stay slightly open. Our technicians tell us the valve and sensor must be replaced together to correct this concern.