Brand New 4runner, rust?

Just bought a brand new 2023 4runner 5 days ago, car only had 80 miles on it. This is my first ever brand new car so I'm not sure if this is normal or not. I was looking underneath, and noticed little bits of rust. Each spot is very small, but there's lots of different areas across the frame. It's this normal? I worry that rust tends to grow and spread.

 

First ever new vehicle... Okay, here goes... Your new 4Runner has crossed the Pacific Ocean on a boat. That took weeks in an extremely salt air environment. On the drivers door post is a placard with the production date of your vehicle. However, that is the date it rolled of the assembly line in Japan, but that does not mean that every component of your vehicle was produced on that day. The frame was likely produced long before and sat in a rack with a bunch of others just like it. The engine? Same thing, as well as the transmission, the differential and a lot of other components. Mix in Covid - and who knows how long some of these items sat in a warehouse in a country surrounded by salt atmosphere.
Your first photo showed rusty threads on a bolt. Got news for you, when that new bolt was installed with a new nut - that was when the threads became virgin steel again exposed to the atmosphere. The oxygen in the atmosphere eats anything man made metal. Some things corrode faster than others. The welds on the frame? You got it - the welding process creates corrosion because of impurities that paint WILL NOT stick to unless thoroughly cleaned by some other chemical process. The frame and welds may get sprayed with some kind of "cleaner" before paint, but I guarantee that it was not a process by hand by someone that cares. Anywhere that you see welds - you will find paint that doesn't stick and flakes off with corrosion underneath. The oxidation process starts immediately after the weld happens - and by the time it gets painted robotically the rust is there. Inside the wheel? Welds with corrosion. Drive train corrosion? Bare metal that doesn't get painted. Sorry dude, unless you are paying for a hand-made car, such as a Rolls Royce or some other $500k to multimillion dollar car - this is what you get.

 

My 18’ had the same tiny rust spots on the frame welds too. I checked several new 4Runners on the dealers lot and they were the same. I agree that it doesn’t seem right but apparently due to the metallurgy of the welding process, paint doesn’t stick as well as the above poster stated.

Fortunately I live in a dry desert climate so I haven’t noticed any rust growth in 4.5 years of ownership.

 

Normal. Like @Slopemaster, I live in a dry climate, so don't see any rust 'growth', and don't pay any attention to those small rust spots. If you're in the rust belt, those would need attention.

 

Normal. Pretty much any vehicle will do this, a lot of the stuff underneath is just bare untreated metal. That said, Toyota does seem especially inept at making rust resistant vehicles.

If you live in area that uses road salt, I would IMMEDIATELY have it treated with fluid film, wool wax, or New Hampshire Oil Undercoat. That will prevent a lot of rust from forming, and keep your undercarriage looking new for years to come.

 

You are right to be worried. If you plan to keep this long term, you absolutely owe it to yourself and your heirs to get this undercoated with some type of greasy product. I used woolwax, but there are a few other good products.

Spray it on the outside of the frame, spray it inside the frame, especially in all the crossmembers, especially on the front three, and especially on the front crossmember that will live in salt spray and dust all winter. Get the rear axle, body mounts, the front LCA’s. Put it on everything except the CV boots and brakes. If you want, get a gallon of the stuff and just paint it on, and use spray cans for the inside of the frame and hard to reach areas. Less messy, and more accurate, but a little more time consuming. I even put it on the transfer case so it keeps that “freshly cast aluminum” sheen lol

These dont tend to rust badly on the body, but I still sprayed the underbody sheet steel. And all the brake line fittings.

Woolwax is great because it’s not noxious when you use it. Some other stuff can be however.

If you live in a dusty area, or you drive through mud, it eventually builds into a nice dry crust, the color of the most recent mud you’ve been through. it’s a ghing of beauty. In warm weather you can wipe it off with a dry paper towel and some pressure from your hand, to reveal beautifully black original paint.




Here you can see the black paint. Also, you can see the weld that couldnt hold on to the paint due to the impurities on the surface of the bead. That rust really didnt spread since I sprayed it a few months after I got it.

 

Its normal. After I received my PRO this past Feb, I did a through underneath inspection and discovered spotted surface rust here and there including on some bolts. I in Cali and not sweaty it. You can try to clean it up and put some preventive coating on it.

Dont worry to much and enjoy it.

 

Thanks for the responses all. I feel better knowing that this is normal. I love do live in the rust belt (northern Indiana), so I had already planned on under coating it. I was just surprised to find it already had tiny rust spots on it from the factory.

 

Just make sure not to use any of the rubberized goopy undercoating. That stuff is terrible.

 

Yup, I ordered Surface Shieldb by Blaster. Should be here by the weekend.

 

Nice, that stuff looks like a good option, I actually am going to pick up some for mine.

 

Anyone applied surface shield yet? I would like to know how it turn out. What is your take on it?

 

That's normal.

 

I think this is on my pro already why is it terrible?

 

Because it’s basically thick rubberized paint. Paint peels eventually for a million scientific reasons. But the rubberized nature of the paint means that it’s peeled, but it still holds it’s shape, and it doesnt fall off.

What that leaves is the rubber paint acting as a container for water…and that water is held tight onto the frame. Also, because the water is largely protected, it has a hard time evaporating. Add salt, and people can get a nasty surprise when they realize their frame is dust behind the rubber.

If you could guarantee that the rubber would never peel, it might work. But that never happens.

Chances are that is was sprayed in a convenient way, meaning, it’s not inside the frame, or on top of the frame members where you cant see. If you work on your own vehicle, you could just be vigilant and wherever you suspect peeling, scrape off as much as you can, especially on the downhill side where water really wants to collect. Every time you work on it, take a look and spend some time peeling and spraying on one of the thinner oil coating options.

I have woolwax on mine, but I still spend plenty of time looking and touching up. It’s too bad these arent hot dipped in zinc, but that’s hard to do at factories due to the environmental impacts

 

I put surface shield on mine this past weekend. It's the only rust prevention I have used, so I have nothing to judge it against. The cans seemed to leak a lot around the nozzle and kinda made a mess. Ordered a $15 wool wax 360 degree wand and it was a disaster. Got the cavities all coated, but I bet half the can leaked out around the nozzle. And wear a mask while spraying it...

 

Do you guys sand the rust off before coating it? Or use a wire brush?

 

I had mine dry ice blasted, then paint touched up, then coated.

 

What is “dry ice blasted”?

 

Totally fucked. Send it back to the dealership

 

Awesome Prevention. Like the painted parts.
Question about the oily parts - would that attract dust, muds and road salt sticking?
Just curious because am still considering Waxoyl application used primarily for Land Rover Rust bucket. They only last 4years

 

Any before pics? What year truck?

 

Re: What is dry ice blasting?

Its literally what is sounds like... instead of using a highly abrasive media (like sand, which also gets absolutely everywhere), or a harsh media (like walnut shells), they use dry ice to attack the found rust and surface contaminants, and remove the weak paint on the frame. So its a clean way to remove rust without stripping good paint off the parts.

Check out sublimesurfacing.com for some good info on the process. That's the company that did mine.

 

It maintains a slightly tacky texture, so it will pick up road grime over time, but that grime won't seep through to the metal. And because extensive surface prep was done, as the honey seal material wears off on those highly exposed parts (after a few years) you will still have a good quality paint barrier.

So far, I don't notice the undersides of the truck looking "dirty" or anything...and I've been on a lot of gravel, dirt, highway, and mud.

 

Its brand new...like, it had under 1000km when I took it in. I want it to be a forever vehicle, so spent money on protecting it right away (including a lot of Expel PPF and ceramic coating).

So that being said, rust was very, very minimal (isolated to welds, mainly)

Before blasting and paint touch up:


After blasting and paint touch up:


After coating:

 

Questioning the same

 

I talked about it a few posts up, but for more in depth check out that Sublime Surfacing website I mentioned.

 

Since you live in Indiana you likely have a Krown Rustproofing there. It's worth considering IMHO. Here is a Link that I posted last year. It goes in for it's third application next month in May. I'll take photos again - just before they apply to see how the second application held up. Should be interesting. What ever method you decide on, now's the time to start when it's new.

https://www.4runners.com/threads/krown-rustproofing-update-year-1-report.26094/