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2004 Toyota Corolla is rusting. Can I slow the process?

I have a 2004 Toyota Corolla with 105600 miles on it that I bought new and it has been a great car. I plan on keeping it for a long while longer and can’t afford a new/newer car right now. It is just starting to Rust by the rear wheels near the bumper on both sides and down on the rocker panel at the rear wheels as well. I saw an 06 and a 04 Corolla on a used car lot the other day with rust in the same spots and a lot worse and they had twice as many miles on them . The 04 had holes the size of softball. The there is also a Corolla that’s probably an 05 or 06 by the grill in the parking lot where I work in worse shape I as well. Live in Iowa and use salt on roads in winter. I think mine might have been help by having to have had body work done a couple times after the city Garbage truck backed into my car while it was parked and me about four years later not realizing I was dinging my car up whit the butt end of my ice scraper trying to get at at least an inch and a half of ice off after work during an ice storm. ( those are separate stories)

My question is that since I am planning on keeping the car longer and it gets regular maintenance by a trusted mechanic Do products like POR15 really work to stop rust from getting worse if I put it on the undersideinside of the rear wheels and riocker panels?

Thanks, Noelle

the bad news is: once rust develops, it can not be completely removed in an economical way :frowning:

now it will be quite involved, effort-wise, to even delay it, especially considering you live where salt is regularly used

if you are DIY-er and plan on doing it yourself, probably few economic solutions might be found, otherwise, I would not waste money on a “professional fix”, as the cost will easily go for the double that they car is worth


Only if you get to both sides of the rusting surface, inside/outside.
Putting it only on the outside will trap the moisture inside and make it rust faster.

Fix the rust first then have the entire car rustproof. Krown is the best rustproofing treatment you can get.My 99 Corolla was rustproofed with the stuff back in 2002 and still look great.I live in the rust belt.

The rust you can see is about 30% of the rust that’s actually there.

I also live in the rust belt. And once the rust starts, it’s nearly impossible to stop.

I drive my vehicles until the rust gets to the point where it makes the vehicle unsafe to drive.


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Whatever you decide to do, you should probably take the car to a mechanic who can put it on a lift and check to see whether the rust you see is also damaging the structure of the car to the point where it is weakened and becoming dangerous.

The structure of the car for now is fine. I just had news brakes and an oil change done a couple weeks ago and have a VERY trusted mechanic where I have been taking my cars to since I first got one at 17 and am now 42 and my family goes there as well and know everyone there.

I got a POR15 kit and for $24 and am going to give a try on the underside… I know it’s not going eliminate the rust and that would require a body shop and reprint to make it look right but hopefully it can curtail it for a little while. I might look into Navy Jelly and contact my Uncle who buys used cars and fixes them and sell them which has done for years and used to teach auto

Gee, that seems like the first place you would have contacted.

I know. He lives 2 1/2 hours away though

I would sand each spot until I got to bare metal. If that results in a hole in the metal, you need to get at the back side and do the same thing there.

If not, just hit it with metal primer, then touch up paint.

Many body panels are available on line at low prices. Having a body shop replace rusted panels and paint them to match may not cost so very much, if they use aftermarket and not OEM panels. It would take a long time for rust to appear again. Worth some inquiry.

add “, then rust converter” in the middle, and OP will be all set

How many more years do you plan to keep the car. If the rust is not causing structural you may live with it.

At least three more years is how long I plan on keeping it. Maybe more. At the moment I don’t plan on trading it whenever the time comes to get a different car. I plan on giving it or selling it for a real low price to a friend of mine who who has MS and not not much an income as a result. It depends on what shape it’s then as to sheathed it will go to her. She has an old 95 Honda Civic

Ive used POR15 extensively over 25 years. It will work best if you remove any loose pieces and the surface is clean and dry. That’s it. Brush it on. Beware the warnings about gloves etc. It sticks on skin as good as rust!

Try not to use it from the can if you are only going to use a portion. It cures with humidity. Pour some into a cup and lightly cover the can w/lid to keep it fresh.

If you don’t use all of it and want to save remainder, put a piece of saran wrap between lid and can or you’ll never get it open again.

I’ve had excellent results from full frame off restorations to just slapping it on rusted surface areas like you plan to do.


Make sure when you wash the car, especially in the winter, but even in the summer, to spray all four wheel well areas. Put the hose into the wheel well and move it around from front to rear, and point it toward the top of the wheel well too, to get as much road salt from that area as you can. Do the same along the rocker panels as best you can, especially right behind the wheels. You are right that the rust problem you are having is probably related to repair work done due to an accident, the Corolla (as is the case with most newer econobox cars I imagine) is pretty rust-resistant as manufactured at the factory.

Besides keeping the wheel wells flushed clean – this might be necessary to do every week in the winter due to the road salt — you could try spraying the parts that seem to be rusting on the inside with the motor oil you drain from the engine during services. As mentioned above, the only actual “solution” to rust is having all that rusted stuff cut out and new metal welded in, or the panels replaced. But I’ve found from dealing w/rust problem on my truck in visible areas, that rust progress can be slowed way down by removing as much of the rust as you can with abrasives (sand paper/steel wool/rubbing compound), then giving the area a little spray paint from a can treatment, then keeping the surface well waxed, at least twice a year.


You live in California.

In the rust belt, when rust starts eating away at your vehicle, all you can do is sit back and watch.

Because no matter what you do to prevent the rust, the rust returns because the vehicle is subjected to the conditions that creates the rust.



The rust on my car is no where near as bad as the other Corollas that were around the year mine is. Those were much worse. I think the body work that had to be done to my car due the garbage truck actually helped delay the rust process on my car a little. I bought the car in and it got backed into August of 2005.

I live in Iowa and not California.

No arguments there, but there’s a definite difference between the amount of rust-resistance designed into my truck compared to my Corolla. I’m not sure what they did on the Corolla, but whatever is was seems to work pretty good. Although I live in Calif, I have driven my Corolla over the years in the winter on salted roads many times. True what you say about Calif cars tho. My poor truck would have been crushed years ago had I not moved it to California when I did.