I have a 2003 f150 4x4 scab with a 5.4 L it has a little over 6000 miles and i put a k&n air system on it at about 1500 miles i have noticed in the last week that when i go out to go to work i start it up and and put it in gear that a strong sucking sound is heard it is coming form the K&N it only does it when it is in gear and only for about 30 sec when i take off if i stop at a store or somthing like that and get back in and start it it does not do it anybody else heard this ????? hear is a list of the mods i have done to it.

TIA John

 

Normal. Both my vehicles do that.

Mike

 

thanks for the reply.

 

If you installed a cold air intake "system" ,from what I've heard,some of them you do hear a sucking sound and that is normal.If it is just a k@n filter in the stock housing,no thats not normal.Make sure the housing is completely closed.