'04 Cayenne V6 idle intake leak noise?
 

Hi all, was wondering if anyone here can help id the source of my intermittent engine noise issue. This is a '04 Cayenne V6 with 65k miles.

After a warm start the engines idles normally for about a minute then a noise comes on gradually that sounds like an intake leak. When I rev the engine, even just cracking the trottle plate, the noise instantly goes away, but it slowly comes back. Here is a video...the noise starts up at about 50 seconds in. The noise is loudest in the center of the intake on the right hand side. At the end of the video I crack the throttle and make the noise go away temporarily.


What do you think is causing the noise?
Thanks.