Driver door sill rust...

25 years ago they used real paint.

Nothing to do with China. Everything to do with EPA.

 

Unfortunately I was out of town the week I got it in for repairs, so I didn’t get to see it. The only thing I know is they told me it wasn’t the body, just a flaw in the paint. They pulled back the carpet and found a few others. I know they peeled up the sticky door sills and replaced them.

 

Update on this as I was scheduled to have a regional rep check out the rust. He was shocked and has never come upon this so he says. It is scheduled for repair next week. They also have agreed to pull the adhesive sill protectors to search for further problems. One thing I’ll note also is that my truck is heavily fluid filmed to say the least, with coating inside the rockers multiple times, no way this came through from the inside somehow.

 

I worked in automotive for a long time and have seen this before.

In the picture of the floor you'll notice the corrosion is predominantly in areas where the spot welds are. When you spot weld, you damage remove the zinc/galvanizing on the metal.

In the pictures where you see the corrosion on the sills you'll notice spot welds above areas where the "spatter" has corroded and bubbled up under the paint. You may notice there is a spot weld with a different shape/contour vs some of the others.
When you spot weld you have to control the orientation of the weld tip surfaces to the metal being fused, You also have to control tip pressure and amperage during the weld.
Screw one of those up and base material is "squeezed" out and will spatter on adjoining surfaces, no galvanizing on it so it will rust much easier.

Sometimes the spatter is only partially attached and some paint/primer flows underneath and so therefore there is an under spec film thickness between the spatter and the environment.

When you see videos of robots going into the cars and spot welding and you see sparks, remember:
"Sparks are bad, M'kay"

 

In short this is what the body shop manager was assuming had happened.

 

This picture is a TEXTBOOK example of what I was saying, looking at the spot welds left to right,
First two have the inner surface parallel to the welded surface,
Last on the right you can see that the LH side of the weld is deeper than the RH side, the spatter is on the 4'oclock position to the right,
Material "blew out" because the tips were not in the correct orientation to the welded surfaces.
Programmer of that robot just rotated the "head" of the robot to do that third weld and did not reorient the other axis of the robot arm to get a proper orientation.

There I've almost finished a Toyota "5 Why"....

 

Another area to FF soon

 

Ive seen far worse looking spot welds in my day... technically the two welds should be on the same plane if robot was programmed correctly that shouldn't be an issue. Also there should be people looking for expulsion on welds and cleaning it up.

 

I know in reading about the differences between the Texas and Mexico Plants, Texas was all automated and Mexico was mostly hands on including welding inside the Cab, wonder if there would be any difference in the end results.

 

Absolutely. If they are actually spot welding 'by hand' (lift assist units on weld guns) the welds generally will be of lower quality. Could get into a bigger explanation but theree are pros and cons of both. Weld locations / weld quality will always be better with a robot, but lift assist units SHOULD 'even themselves out'- ie, when the gun is closed, there's no rigid structure holding the gun (robot) and it should normalize itself to the weld plane.

A robot just goes where it's programmed to. There is equalization build into (most) guns but it's only usually in one direction

 

Appreciate all the input from someone knowledgeable on the matter. As far as the spot welding automation talk goes my truck is of Mexican descent. I at least hope everyone checks out their own trucks to stay ahead of a bigger problem in the future. Funny thing is I was talking about the problem to my brother in law who had recently traded his 2012 double cab Baja in on a t4r and extensive rust below the weather strip and on the cab floor discovered too late was the underlying reason for the trade.

 

Wow, at least he noticed it and could get rid of it before it got any worse.

 

Usually off-plane welds don't really cause an issue. You should see how bad the spot welds are on my 96 Golf (Mexico built of course) I don't think there's a nice weld anywhere

 

Mine is from the Mexico plant too.

 

They paid for my auto body shop to remove all the old paint and rust and repaint with epoxy primer and paint then replace the weather seal.
I did not get pictures during the repair. There were many spots on the door sil which had spot rusting along with places under the rubber seal
I did not have sil protectors on vehicle. Obviously if you have bubbling it needs to be addressed. good luck

 

Just checked mine & it also is rusting. This 3rd gen truck is a nightmare of problems.

 

That does not look good but I am sure they will take care of it under warranty

 

Don't worry too much. That looks exactly like mine did. It's just loose stuff that got under the paint while it was being painted. Not actually part of the body of the truck. Still covered under warranty though.

 

Dealer is going to hate me on my next visit lol. This is getting added to the already long list of items I need to be completed.

 

I can honestly say that this was handled well only after pushing hard and then discovering the rust under the seal. Don't assume the warranty will just cover it without a fight.You could just copy this whole thread and give it to them once they say this is the first one they saw!! Other than this I love the truck. I average about 22.5 MPG in winter and about 25 in the summer. My best tank is 26.7 MPG As good or better than my 2005 4 cy reg cab 2wd Tacoma.