Sometimes when I close the drivers' side door there's a rattle that seems to be coming from underneath the truck somewhere. It almost sounds like a baby rattle.

Anybody know what it could be?

2010 F-150 FX4 SCrew.

 

Loose screw inside the panel? They are easy to pull off and check.

 

I have the same thing. Also when driving. Going to have dealer find it. Its behind driver seat in the back panel. There is airbag stuff behind panel.

 

Same...

 

It is the vent flaps on the back of cab (air pressure change when shutting the door causinge them to flap which sounds like rattle).

 

Mine happens when I'm driving.

 

The vent flaps are for the first post.

 

dealer says the rattle is my aftermarket speaker wire rattling. Where it enters the back of speaker. There is a small cross-over attached to speaker thats probable rattling. I will check for my self

 

I had a similar rattle in my 2012 screw. It was really noticeable going on dirt/wash-boarded roads. I took the drivers side door panel off twice before I finally found it. I had to take the black plastic off (most of the way off) behind the inside panel and found a bolt almost directly in the middle of the door that was loose. Tightened it up, and all is good now. Looks like someone just barely threaded it from the factory and forgot to tighten. Was a little disappointed with the craftsmanship on a $50K+ pickup, but these things are mass produced and humans make mistakes I guess. Drove me nuts until I found it though. Good luck!

 

Many many years back, my grandmother bought a brand new 1957 Buick. The thing had a rattle in the driver's door from day 1. When the dealer tore the door open, they found a beat up lunchbox in there.

 

Some have had a loose wiring harness inside the door that was causing a rattling sound when closing.

 

I've got a rattle in the rear drivers side door I haven't pulled it apart to figure it out but i'm pretty sure its something with the window regulator in mine since the tint is gouged a little forward from center and about 4-5 inches up from the bottom... Glad it's on that window I never see it unless i'm cleaning the truck and whiping it off... otherwise i'd be retinting the entire truck so they match...

 

I fixed the rattle. It was the crossover from my speaker. Wrapped with a piece of carpet pad, now rattle is gone.

 

Mine were doing that as well. I had to trim out part of the foam that goes inside the arm rest..and put the crossover there...