Any ideas on how to prevent this from getting worse?

So my paint in my driver side door sill is bubbling and seems to have rust coming up. It appears it may be under the door sill protector as well. I’m not overly concerned as it’s in my door sill but I would like to prevent it from getting worse or spreading. Any ideas? I was thinking maybe sand and primer, followed by touch up paint? I’m no paint or rust expert so any advice would be appreciated. I’m no longer under warranty. Here’s a couple pics.

 

There is a TSB for this, take it to the dealer and check if yours is covered. Rust is longer warranty than your base warranty.

 

Really? Well that’s good news, thanks!

 

Why is rust still an issue in modern vehicles.

 

OP Thanks for the post. When I Fluid film my 2020 shortly when the temps warm up I'll be sure to inject some FF into the shown holes in the door gaskets on the bottom of the door sills ....

 

When I FF my truck, I pulled all the rubber plugs in the rockers and sprayed a ton inside the rocker panels.

 

Salt and oxygen.
Edit: oh, and metal...

 

They only note it under the 3/36 unfortunately in the tsb

 

True, but their rust warranty is 60 month unlimited miles. So there is a chance of getting it covered anyways.

 

That’s good at least, a chance to fight it. Unlike the third brake light leak! If only that leak caused rust too

 

Oh boy. I'll have to check mine in the morning. It's an October 2015 build and has so far had literally every issue the 3rd Gen can have, lol. Just got my 3rd brake light fixed but not after it was all soaked in the headliner, soggy, and mildewey on the cloth items I kept behind my back seat.

I'm well out of warranty at 65K/52 Months. But I was fortunate to fight enough to get that fixed since it's very widespread and we've bought dozens of Toyota's as a family at this dealership including the Taco brand new off the lot and the 09 Tundra I had traded in for it. Only got through by general manager approval. Service writer tried to turn me away multiple times but hey.

 

Wash your truck and wax the door sills. Lack of attention to detail. I would be pissed if my 18 looked like that. Try the dealer but don’t be surprised if they turn you away. I would cringe if my plastics and metal looked like that.

 

Pull the sill trim up, then pull the door seal off. You will be able to see if there is any rust right there on the pinch weld.

 

Well good thing it’s my truck not yours. Also some places in the nation have four seasons. SC isn’t one of them. I’m currently still in winter.

 

We had rain, hail, snow and 45 degrees sunshine all in one day (today) here in MN.

 

Yeah I hear ya. Dumped 5in of snow here yesterday, today mostly sunny and 40’s.

 

Yea I’d have to say that would not prevent this regardless (you may notice it sooner but that’s it). The bubbling you’d see is not the first signs! Pull the sill scuff plate and it will originate at the pinch weld caused by water running down the weatherstripping. Look at the tsb and read the repair procedure- they add a sealer to the spot weld along with a clear flange tape

 

I think it's because of water based, more eco friendly mandates.

 

Due to legislative orders all automotive paints are water based...in the old days of oil based enamels paint would last decades...