Been noticing a rattle occasionally. Seemed to be behind me. Now it’s on every bump and our town roads seem to want to compete with Beirut. Narrowed it down to the driver door. Pulled everything out of the pockets, still there. All other doors quiet as a church mouse. Sounds like an operating rod either disconnected or is missing a foam sound dampener. Dealer appointment next Tuesday. I’ll have them reflash the transmission for hard downshifts at slow speeds while I’m there.

 

I've got the exact same problem in my 2018. Interested in what they say.

 

I noticed the rattle in the door a few months ago. I'll check tomorrow if it is still there.

 

I recently posted about the same thing on my 16. Rattled for a long time, every time i shut the door. thought it was something wrong with my tow mirror.

anyhow, i removed the door panel and found a paint can opener inside.... i still don't know if it got there from the body shop who replaced a broken window (most likely) or if it was there from the factory.

either way, it is easy to remove the door panels and look for yourself.

 

It’s only a bit over a year old and under warranty or I would deal with it myself.

 

My truck has a rattle where the door panel meets the actual door (driver's side rear door). I have been meaning to put just a little double sided tape there to stop it but haven't gotten around to it yet. That may be the source of your rattles so check there to make sure before having to pull the door apart. In the meantime, I bought a new car seat for my son who is growing and now it sounds like I am driving an old school bus especially without him in it. Good news is I can no longer hear the problem with the door lol.

 

My 2018 F150 Lariat SCREW had a occasional rattle in the doors, kinda sound like its behind you.

I first isolated it to the drivers door by pressing my leg against the door to limit its movement as I drove. It's the movement between the latch in the door and where it grabs the Striker Assembly (the black U shaped catch) on the B pillar if your working on the front door.

Want to quickly isolate it, just start by rapping a few turns of black electrical tape around the front part, the leading edge of the loop of the Striker Assembly where the door latches to the body. I usually put on a few extra turns (probably 4 turns total) of electrical tape on it,. I don't expect the door to close at first, nor do I force it. Now I start removing the excess tape, 1/2 or 1 turn at a time, till it closes with minimal to no felt friction drag on the tape. You are looking for just zero clearance to a maximum slight drag. Now that you know you have a tight fit, time to take a test drive.

What the dealer has done to re-adjust my door latches is move the Striker Assembly on the pillar. Problem there fix does not last forever as the weather stripping settles into its new tighter fit.

The problem is there is some really heavy duty lock-tight adhesive on the two Torx screws that holds the Striker Assembly to the pillar. The first dealer technician damaged the Torx head screws trying to back them out enough to move the loops, then had to order new Torx screws. I was speaking to a auto body repairman and he said sometimes the two Torx screws (factory calls them bolts) that hold the Striker Assembly in place will twist off before coming out.

Sometimes you can see ware on the Striker Assembly where the door has been rattling against the Striker Assembly as you travel down the road. At least one of mine had ware past the black covering and into the Striker Assembly metal surface, they ordered a new one. I have looked a few other F150 SCREW a couple years old or more with no ware at all to the Striker Assembly black surface. One Truck had in the range of 60,000 miles on it with no sign of any ware to the Striker Assembly where the door's latch grabs it.

I think the latches in the door, when closed don't fight enough around the Striker Assembly, that gap then becomes an intermittent rattle as the body flexes and the door moves a bit going down the road.

COVID risks are keeping me away from the dealer right now.

The black tape stops the rattle and stays in place quite well over many miles. Tape, certinally not a factory quality fix but it works.

Striker Assembly