For Christmas I got a K&N intake for my 08 with the 4.7.
It's quite loud with a resonant burble type sound from about 2100 to 3700 if you're on it hard, then quiets down above that. (still louder than stock but lacking the loud burble.)
I'm concerned that it's setting up standing waves in the intake tract and diminishing performance at best, and doing damage at worst.

Does anyone else have the aircharger on an 08 or later 4.7?
(different heads and intake from 07 & earlier as I understand it.)
Has anyone had their engine dyno'd with this setup?
If so was there any point along the curve where the K&N caused it to lose power?

I installed it before a trip and did get better mileage by 1 to 2 mpg.

Thanks to all in advance.

 

Can this sound be described as a metallic fluttering sound?

 

There's no "metallic" aspect to the sound in my opinion. A deep burblely roar. as though the intake was vibrating heavily. All the connections are tight, I can't find anything that's worked loose or shows wear on the outside of the intake. I'll see if my iphone can take a video with sufficient audio to be worth posting.

 

K&N takes make the truck have a louder growl to it.

 

I'm used to the louder intake honk with the K&N's on other vehicles I've driven with them. This is louder. I listened again, and it doesn't sound metallic, but "fluttering" like Hammer asked about, is a part of it.
Could the throttle plate be vibrating?
It only happens under heavy acceleration. I haven't revved it up too much in neutral to be sure, but it sure seems like it needs to be under load.

 

It's the EGR, I think the flutter sounds a little metallic but that could be cause my intake tube is chrome. But regardless, I'm sure it's the EGR valve you are hearing. Perfectly normal, you just don't hear it stock because the "Hemi Hat" baffles it...

 

Where is the EGR on a 4.7?
I assumed it was something larger, as I thought the EGR was a small valve (similar to the PCV in size), and this sounds much more substantial.

 

This comes up about once every two weeks. It's the EGR. Here:

http://lmgtfy.com/?q=egr+noise+with+cai


If it really bothers you, remove the CAI or get a baffle for the EGR valve. Of course the baffle restricts air flow which I'm assuming is the reason you put the CAI on in the first place...

 

Leave it there long enough and you will get used to it.....lol