So yeah....spent the $108 for chrome horizontal bar grille inserts off Ebay. Included grille and bumper filler inserts. They installed OK and look real good. One problem. At certain speeds there seems to be an audible whine or humming sound coming from the front end. At 70 MPH it is real bad. Not good. The grille inserts are the only thing I changed.

What in the world is going on here? Anyone have an idea?

 

Maybe the aerodynamics of the grill is catching wind and making the noise. Maybe it is the CAI if you have one or a bearing on one of the idle pulleys or something else.

 

If they were easy to install, you can confirm they're the source by removing them again. If the sound goes away, you know it's the grill.
Possibily they're not secure enough & the harmonics of them vibrating at high speeds is causing the "hum". either that, or it's just a whistle that you'll have to live with

Before doing anything, I'd remove them to see if the noise goes away.

 

Might just have to fab something up to support them a little better. Maybe as simple as some well placed nylon zip ties?