high pitched sqealing niose when engine is under load on 2008 Ford F-350 Super Duty

This truck has been to the dealership they cant figure out whats causing this noise and its not the pulleys or belts or belt tensioner. When your driving and put the engine under a load it makes a squealing noise almost like a bearing going out. The most skilled people e dealership just said that they dont know whats wrong with it after a day of looking at it and sent me on my way i think their not the most skilled techs out there

by in Hopkins, MN on January 25, 2011
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2 answers 1 comment
ANSWER by , January 25, 2011
It's hard to comment without being able to hear the noise first hand or be able to do some diagnostic tests. If its still under warenttee perhaps you have to try another dealership or contact Ford North America customer Service.
COMMENT by , January 26, 2011
after about 10 pounds of turbo boost it makes the noise to us it sounds like its coming from the turbo its a fleet truck 97000 miles were gonna try a stethoscope and try to pinpoint it
ANSWER by , January 25, 2011
Read this bulletin, it may be related: ISSUE: Some 2008 F-Super Duty vehicles equipped with a 6.4L engine and built before 6/18/2007 may exhibit a gurgling type noise coming from the heater core. It has also been described as a rattle or scraping noise. It has also been incorrectly identified as a torque converter concern. ACTION: Follow the Service Procedure steps to correct the condition. SERVICE PROCEDURE Bring engine to normal operating temperatures. Raise engine RPM to 2500-2900 range. Using a hose clamp tool, crimp the heater inlet hose. If the noise goes away, replace the inlet heater hose. If the noise does not go away, proceed with normal diagnostics. NOTE: DO NOT ADD AN ADDITIONAL RESTRICTOR TO THE LINE OR MANUALLY MOVE THE EXISTING RESTRICTOR. NOTE: DO NOT REPLACE THE HEATER CORE. PART NUMBER PART NAME 7C3Z-18472-K Heater Hose (With Auxiliary Heat Controls) 7C3Z-18472-L Heater Hose (Without Auxiliary Heat Controls)