how is everybody.i have a thumping sound coming from under hood when i shut down. kind of sound like wings flapping.i looked under hood and found no birds. something tells me it may be turbo spinng,occurs for about 5 sec after shutting down truck.truck still has same power,no loss that i can tell. tried shutting down with hood up and it aint the fan .does anybody have any insight on what this might be TIA

 

remove tha air cleaner pipe were it ataches to the turbo and (with the eng off!!!)look to se if the fins of the turbo have been sraping on the housing or see if you can push the nut far enuff that the vane or fin will touch the housing......if so the noise is probably the turbo and it time for a rebuild or replacement!!!

so the fan blade has compleatly stoped and the sound can still be hered!