Especial86

iTrader: (1)

This could be a whole host of issues for everyone.... If that foam strip is not a problem then look into a possible sluggish or dirty IAC (idle air control valve), this is located on the throttle body... The CMCV plates that are servo actuated inside the intake manifold are also a possible culprit... They open up after 2000 RPMs to allow more air to flow through the intake runners, I believe there could be issues with them opening too early causing too much air to flow at a low rpm, this would create a bogging, moaning, droning sound...
I have a volant CAI I can definitely hear and feel the difference when those plates open up...(around 2000 RPMs depending on throttle position)...It sounds mean and the truck pulls very hard...

TxCustoms89

iTrader: (1)

Haha i asked if that thing was important a long time ago and never got answered guess i know now

theduke308

Put your original intake back on, I have not heard anything but horror stories from CAI on these 04-08 trucks because it makes them run lean and they are extremely close to lean from the factory

leopold

Did this fix on 8/6 and mine seems to idle a heck of a lot better.

allinon72

Just replaced this foam with high density foam....wow my engine is much quieter. It fixed a humming noise described in this thread:

https://www.f150forum.com/f4/humming...cks-up-162141/

The truck also seems to pull harder. Everyone should definitely check there's.

theduke308

Amazing what a piece of foam can accomplish!

allinon72

I agree this should be a sticky.

bobkyle2

Stickied

theduke308

thanks bobkyle2

gforceman

I replaced that strip of foam the day I brought my truck home the old one was all raggedy. Used the self stick door foam seal for your house. Works perfect