One problem related to engine turbo-charger has been reported for the 2003 Ford F-550. The most recently reported issues are listed below.
The contact owns a 2003 Ford F-550. The contact stated that the vehicle experienced a severe loss of power and smoke was coming from the exhaust pipe, due to the unison rings failing. The rings are a part of the turbo charger on the engine and the contact had to have them replaced twice. The dealer stated that this was a known failure and that it was not covered under the warranty. The dealer placed nickel plated rings instead of the steel rings on the vehicle and the problem seems to be resolved. The failure mileage was 1038 and the current mileage was 9500.