whistler

[matlock55]

i have a 2006 f350 crew 4x4 w/ drw and automatic w/ 25k on the clock. just recently from under the hood, an ear piercing whistle developed at approx 1250 rpm on startup and while cold, but can vary between 1000 and 1500 rpm. it has been to the dealer a couple of times for this problem, but they are unable verify the condition. any ideas?

[stump0331]

bump....................