One problem related to engine has been reported for the 1999 Ford E-350. The most recently reported issues are listed below.
The contact owns a 1999 Ford E-350. The contact stated that the spark plug has blown out of the head due to the lack of threading needing to keep it in place. The mechanic informed him that the failure has occurred three times within the last five weeks. There are no recalls available for this failure. The mechanic also stated that this could be due to a design flaw. The VIN was invalid. The failure mileage was 139,000 and current mileage was 140,000.