Some 2011-2012 Ford F-Super Duty 250-450 trucks equipped with the 6.7L turbo diesel engine may exhibit a buzzing noise from under the hood while the engine is running and/or for up to 30 seconds after the engine is shut off. This concern may be due to the wastegate control valve vacuum harness causing the wastegate control valve to resonate.
1. If the wastegate control valve emits a buzzing noise while the engine is running and/or for 30 seconds after engine shut off, this TSB applies. If not, this bulletin does not apply. If yes, proceed to Step 2.
2. With the buzzing noise present, disconnect the vacuum hoses from the wastegate control valve. If the buzzing stops, proceed to Step 3. If not, this bulletin does not apply. Refer to Powertrain Control/Emissions Diagnosis manual for normal diagnostics.
3. Replace the wastegate control valve vacuum harness.
The replacement vacuum harness is available under part number BC3Z-9D430-E.