airflow meter whistling noise?
 

Gearheads, About 24 hours after an engine swap the airflow meter started this whistling noise that at first sounded like a slipping belt,a little light tapping confirmed a change in sound then back to a constant whistle from the afm,at first I thought vacuum lines where crossed,but why the delay?,or is it an internal leak in the afm.Any help would be appreciated!.