Annoying whine from inlets

[RUSSO]

I've had an annoying little whine for some time and initially thought it was the main inlet butterfly valve. But after replacing the valve noise persisted and now getting louder of late. It's coming from the top inlet area when you remove the covers and sounds like air being sucked in almost a whistle. So I'm wondering if anyone has experienced anything like it before or do I remove the upper and lower inlets to check the gaskets.
:help:

Quick video of the whistle;
Video

 

[Lankan]

Phil, I was down at Scott's workshop over the weekend and happened to mention this - sent him the video you posted up as well.

Scott thinks that this is most likely to be an intake related issue, specifically around the plenum area. He mentioned a test that can be done to pinpoint the source. Why don't you give Scott a call?

All the best.

 

[Jamesv6]

Do you have plenum spacers?