K&N question

[DDean]

Just installed a K&N CAI on my 07 4.7l. Ive noticed the change in engine tone and everything they promise. Ive also noticed at times a faint whistling sound sometimes not all and sometimes what kind of sounds like a crackling sound. Is this normal?

 

[KGBIGCOUNTRY]

Your hearing the cone pull in the air would be my guess. If you were having running issues I would say its not seated or a sleeve is lose.

 

[MegaMouseGW]

The change in tone is normal for a CAI system. It is actually masked with the normal air box which acts like a muffler for the intake. Now for the whistling that depends. If you have a throttle body spacer then that is what is causing it and it is normal. Sometimes the air being drawn through the air filter will also cause a low whistling sound. The crackling might be a different issue though. Check to be sure that all the hose clamps are tight and in their proper place, and make sure the CAI is properly installed. Mine came loose at the throttle body once and when it did it started to make this ungodly noise. Kinda sounded like a cat in heat.

 

[Casper]

Yup--K&Ns sound like a Hoover under the hood at idle

 

[Redtruck-VA]

I would guess the whistle is associated with the 4.7 IAC design. The 5.7 doesn't have a specific port like the 4.7.

 

[hemihustlin]

My truck makes a very high pitched (almost a dog whistle lol) whistle that goes with rpms and throttle %
It only whistles when you get into it, at WOT just before it shifts it sounds like a spooling turbo lol
I have the stock intake and the only thing ive ever done to the tb was clean and ground (remember that thread?), its been a while but im pretty sure it did it before as well.
So i attribute it to the massive amount of air flowing through, and maybe a little piece of plastic sticking out somewhere in the intake...

 

[DDean]

Thanks for the input guys. Ill check to make sure everything is tight still. Was just concerned cause when i first heard it i thought the sound was coming from a speaker

 

[Wolfhound]

The only thing that I can think of is that you put the air temp sensor back into the tube sideways.