By on July 8, 2013

TTAC commentator Kovalove writes:

Hi Sajeev,

Long-time lurker on a daily basis for over 5 years now. Not sure if this is a worthy question for Piston Slap but here we go: In about two weeks’ time I’ll make my final payment (0% loan ftw) on my 2008 Mazda3 GT 4-door (‘S Grand Touring’ in US spec) with just over 97,000 km. It has served me well with no at-cost repairs other than routine maintenance (some minor stuff was covered by warranty). I have been looking forward to payment-free living and would happily keep the car for many more years, but one thing has been rattling around in the back of my mind…

I live up in the Great White North in the Toronto area where road salt is used from November through to the end of March. After winter 2012 I noticed some early signs of rusting on the inner lip of the rear wheel openings. I was annoyed but not really surprised as this is a well documented phenomenon with Mazdas. I regularly see ‘3s a couple of years older than mine that are rusting badly in numerous areas on the sides and rear end.

Supposedly the 3’s resistance to rusting was improved with the refresh in 2007, but only time will tell for sure. My question is whether there is any financial sense in getting rid of the car now before the rust gets serious, especially given the inflated used car market? For what it’s worth, I will be debt-free with the repayment of this loan. Presumably a badly rusted car would plummet in value despite being otherwise mechanically sound? According to many reports, repairing the rust on these cars is a mostly futile exercise and it comes back quickly. Thanks in advance!

Sajeev answers:

Ah yes, we are revisiting the rusty Mazda problem for the third time in this series. Too bad the 3’s mild redesign didn’t/couldn’t address this problem, and it appears Mazda Canada’s warranty doesn’t cover rust damage.  Did I misread that part with the exclusions?

“Damage or surface corrosion from the environment such as: Acid rain, airborne fallout (chemicals, tree sap, etc.), salt, road hazards, hail, wind storm, lightning, floods and other natural disasters.”

Don’t take my word for it, read your owner’s manual (RFTM) and verify.

Now someone can quickly repair the rust if it’s small/localized (DIY is not impossible, either) and buy more time before the Rust Lord takes over. But will it buy enough to justify ownership to you? And it is worth it to your pocketbook if you can sell it for a price that makes you happy and gets you into a newer car that’ll make you happier? 

Now that’s the real question, me thinks. So what is your threshold for pain? Without supporting photos or a comprehensive underbody inspection, who knows how much pain you got coming?

Take it from the idiot restoring his “rust free” 1983 Lincoln Continental Valentino: once you tear into a rust repair project, you’ll find more of it. Peep the photo below: I thought my Valentino’s decades old, well-known rust hole under the battery was just that!   But oh noooo, the rust seeped down farther, down to the base of the radiator support.

Now is mentioning my Valentino in the same blog post as your Mazda 3 a fair comparo? Absolutely not! 

We all assume that the “young” Mazda won’t be this sinister: at least we assume this. But you know about them people who assume too much!

Send your queries to [email protected]com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice. 


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39 Comments on “Piston Slap: In God We Rust, Part III...”

  • avatar

    The rust is already deeper than the eye can see. I just saw a 2007 era Camry bleeding red from both rear door handles. I’ve seen it older Camrys in Cleveland area but not that generation. Thwy usually rust at the hidden weld seams around the rear side windows and trunk.

  • avatar

    My circle of car friends are mostly GTA-based Mazda enthusiasts. Rear fender rust is just part of regular maintenance.

    That said: I bought a brand new Protege5 from Ajax Mazda in 2003 and drove it 220,000kms in 10 years. The rust only really started on that car AFTER I stopped getting it Krowned annually.

    If you want to keep the car long term, spend $200/year getting it Krowned.

  • avatar

    I am a big fan of Mazda products. I bought a 2002 MPV back when we were sent to Okinawa in 2007 and absolutely loved it. I liked it so much that I decided that I would replace it with another used Mazda when we came back to the states in 2010 and set about looking for a 2006 MPV once I arrived in Buffalo.

    It turns out they are amazingly thin on the ground here and that the few I found were almost entirely eaten up despite being just around 5 years old. The salt does horrible things to cars, something that was absolutely shocking to me, a person from Washington state where we don’t use road salt. Mazdas seem to be particularly prone to salt corrosion and even ones that are well taken care of just don’t last long if they are driven year round.

    I ended up buying the Ford Freestar that I have written about and it had what I thought were a couple of very minor rust related paint blemishes. Boy did I find out that where there is smoke there is fire. $1000 later I had the panels repaired and repainted but I know that there has to be rust I just haven’t discovered yet. When I do find it, mostly on the bottom edges of the body, I’m right there with sandpaper, antirust chemical and touch up paint. It seems to work, but the handwriting is on the wall. All I need is one more year out of our van, maybe two, before I head back overseas so I am OK with what is happening, but if it was a longer term proposition I would be seriously distressed.

    At this point, regarding your question, I would say that it depends. If you want something new (or expect to make a change in the next couple of years) I think you should move quickly to get rid of the Mazda. If you want to keep it, go after evey little spot, have it rustproofed, inspected and repaired constantly and use it until you can’t use it any longer. Once the rust gets serious, you won’t get a penny for it though, so there is, I think, no middle ground.

    • 0 avatar

      As bad as upstate NY salt is to cars today, it is nothing compared to the old days. In the early 80’s, Japanese cars were Swiss cheese in three years. Most domestics (with certain Fords as the rusty exception) and better Euros got about 5-6 years before the Syracuse salt got to them. By 7 or 8 years pretty much everything was rotted beyond belief. Where letters or tags were drill-hole mounted there were large holes. You could often see the backside of interior panels, window regulators, crash beams, etc. It was just unbelievable. Surprisingly, Omni/Horizons resisted the rust better than almost anything else. It was at this time the scam companies like Zeibart began to make inroads.

  • avatar
    Kyree S. Williams

    This rusty Mazda thing does *not* make me feel so good about checking out the 2014 Mazda6, which I would be keeping for at least seven years. Hopefully they’ve sorted the issue by now…

  • avatar

    Funny this topic shows up!

    Just back from a road-trip vacation and our rental car was a 2012 Mazda3 hatch. Big mistake for me, as my back is still protesting, but sleeping in different beds could be a factor, too, so I can’t blame the car totally.

    Last year I briefly flirted with the idea of buying one of these instead of another Impala, and the constant factor in my mind was premature rust!

    Another Impala it was, and after living with a Mazda3 for a week, I made the right choice for my circumstance.

    However, if it were me facing a car-payment-free life for awhile, I’d keep the Mazda, rust be hanged! Drive it ’til the wheels rust off and save your bucks, American or Canadian!

  • avatar

    As far as factory warranties on corrosion goes, surface corrosion is usually only covered under the basic 3 year/36k mile (3yr/60k-km) warranty that covers defects in paint. Perforations in exterior body panels due to corrosion usually carry a separate warranty which on average is 5 years with sometimes varying mileage in the 100k miles (160k km range), sometimes with no mileage limit. It sounds like at this point you’ve got surface corrosion creeping in.

    If it’s starting on the fender lips, it might be fixable without much metal work if you repair it now. The longer you wait, the more expensive it gets and bigger rust repairs come back faster. I’d recommend getting a few body shop quotes to remove the rust, patch any metal that needs replacing, and repaint as required. Then, invest in some quality oil spray. Make sure they use a thinner deeper penetrating liquid oil inside the body panels that will creep into all the cracks. They will use a thicker waxy but still oily mix on the undercarriage and engine bay.

    This will make a mess at first, but will be worth it in the long run. Since you’re in the slushy streets of TO, get a reapplication once a year. An $80 oil spray is cheaper than any body work.

  • avatar

    My fathers 2010 3 hasn’t had any rust issues although we live in NC so it’s not something we worry about.

    However the paint quality is terrible, it makes GMs paint look top shelf.

    The front end was chipping within 5k miles.

    He loves the car though, 120k miles no problems otherwise
    6 speed manual 2.5

    Edit, leather seats started falling apart at 80k also, pretty sad for such a new car in my opinion.

  • avatar

    You have to get ahead of it and STAY ahead of it; even as much rust as you’re currently showing should have been addressed at first sight. While I’m not familiar with Krown, suggested above, any rust preventative measure can keep it from doing significant damage in the long run.

    Get the car inspected for rust and have EVERY patch of rust sanded and primered at least. Better an ugly patch of primer showing that the car is being cared for than rust blisters showing otherwise when you finally do sell/trade your car. It will make a difference in trade-in value.

    • 0 avatar

      As a follow up to this, if you have a spot that is primered, paint it! Do not leave primer unpainted as primer does not seal the surface and you will get more corrosion in short order.

  • avatar

    I wouldn’t count on the rust issues being fixed in 2007. I looked at Mazdaspeed 3’s around the 2009/2010 model year cutover, and the 2009 white cars were already showing tinges of rust all over the body. On brand-new cars still sitting on the lot. In Dallas, where we don’t salt the roads.

  • avatar

    There are plenty of good tutorials online and a presentable repair can be made at home. Once the rust has been completely removed I recommend using an epoxy primer and having an auto paint store mix up a rattle can of touch up paint; skip the stuff at the parts store.

    To ward off rust inside the panels spray an anti-corrosion agent like Boeshield T9 into all of the drain holes every 6 months or so.

  • avatar

    The combo of road salt and brine spray delivered by PennDOT proceeds to destroy every car that isn’t rust-proofed or brand new…If I could, I’d file a god-damned lawsuit about it. I want to drive my car without having to wash it after every snowfall. This is Pennsylvania, it snows fairly often in the winter.

  • avatar

    So based on the report from DaveDFW, Mazda still hasn’t figured out how to make their cars not rust? I don’t get it… Some of the new Mazda models are tempting, but there’s no way I could spend $20000 or more on a car that might rust apart in 5 years.

    Despite all of the VW hate/dislike on here, they have rust prevention figured out. I just had my wife’s 2000 Jetta up on the lift this morning for its yearly Maine inspection stickah, and the tech said it’s really clean underneath for its age. VW offers the 12 year/unlimited mileage corrosion warranty, which I think is the best offering out there. VW replaced both front fenders for free on my wife’s car when they rusted out due to a piece of foam that VW put on the early A4 Jetta TDIs. And this was in 2012.

    Anyway, Mazda needs to rent some VW engineers or something because the rust association with Mazdas is getting ridiculous.

    • 0 avatar

      I have to admit you are right. My VW Golf looked great sitting there dead beside the freeway and even better up on the ramp truck.

    • 0 avatar

      I would like a metallurgist to discuss why Mazda in particular rusts so quickly. Poor quality steel? Galvanization layer too thin? Lack of investment in key equipment? A Zoroastrian curse for taking a god’s name without paying copyright?

      • 0 avatar

        Agreed. I’m very curious to know the root cause.

      • 0 avatar
        Brian P

        Not a metallurgist but I’ve seen enough body-in-white assembly equipment.

        Mazda is most likely not using galvanized sheet metal for the non-structural panels – outside of the German brands, that’s usually how it goes, other brands aren’t much different.

        Part of the issue likely involves coating/painting. The inside of the panels has to be painted, as well as the outside. The surface finish doesn’t matter so much on the non-visible portions, but it sure matters that the inside parts get coated. If they are not getting paint on the backside of that lip around the wheel opening, it’s gonna rust.

        Even if the body goes through a dip tank, the liquid has to get in and air has to get out of every crevice in order for it to work. If the design leads to an air pocket, or if the gap between sheet metal parts that are spot-welded together can’t be completely filled in or sealed off, it’s going to be a problem.

        The fit between the plastic inner fender liner and the sheet metal is important, too. If it rubs, it’s going to go through the paint. It either has to be clamped in place by fasteners, or allowed to have some clearance, no middle ground.

        Water has to be encouraged to drain out. This can be tricky to get right. Water and mud accumulating on the inside lip of that fender, after it has gotten through the gap between the plastic fender liner and the fender, will be a problem in the long run.

        Very minor details can make a huge difference. VW lately usually gets corrosion protection right, but that foam vibration isolator on the inside of the front fenders on certain Mk4 TDI models caused a problem by trapping water against the sheet metal.

        Doors are usually assembled by folding lips of the outer sheet metal around the edges of the inner door skin with sealant applied to the joint. That is just begging for water to get trapped if the sealant application isn’t just right and/or if not enough paint gets applied to the insides of the doors afterwards.

        There are lots and lots of ways to get this wrong.

    • 0 avatar

      My old Jetta never rusted…It started leaking oil around 40k which kept everything well protected. That and, yes, the deck of the flatbed tow truck likely protected it from any road salt on many occasions.

  • avatar

    Thanks to Sajeev for posting this, and for the comments so far. A little over three months have passed since I originally wrote in to Piston Slap – I still have the car, it’s up around 104K km now. I discovered some more rust along the bottom inside edge of the rear passenger door when doing my major spring cleaning.

    My dad knows a guy at a reputable autobody repair shop nearby so I’m going to take it in and have it inspected and see what their thoughts are, for starters. I’m vain in the sense that I wouldn’t attempt a DIY job of fixing it at the visual expense of it looking like a DIY job. I’ve worked pretty hard at keeping it looking young – annual claying, regular waxing during the warm months, etc. So the rust is a real downer!

    If I were to get it “rust-proofed” at somewhere like Krown, would I first have to get the existing rust dealt with in order for the treatment to be effective? I don’t think it was stated in my original question, but the car has never been rust-proofed. I researched when buying it and opted not to.

    The thought of it being a “now or never” type decision re: selling it, as some have suggested, is a bit worrying. I didn’t have any sort of set timeline for getting rid of the car, aside from not wanting to drive it until it’s a rust bucket and falls apart. I also wouldn’t mind hanging on to it in part because there simply isn’t another car out there that ticks all the boxes for me right now, within my price range anyway. So in that sense it would feel like a forced decision. #firstworldproblems?

    • 0 avatar

      Don’t get rid of the car if some minor surface rust is just starting to creep in. Get the body shop quotes to remove the rust, seal the areas, and repaint. If it’s only minor rust coming in at the edges, they will likely be able to fix it without any or only minor metal work.

      Once that’s done, get it the professional corrosion treatment. Getting corrosion treatment over existing corrosion will only slow it down, get it fixed, then get it coated.

      Krown is popular, but there are many different places under many different names that will do it as good or better for the same or cheaper prices. I use an independent shop locally that undercoats the body, chassis and engine bay with a oily/waxy snot coating and then sprays a much thinner oil (looks like automatic transmission fluid) inside all the body panels which seeps into all the cracks.

      Every vehicle of mine and other people’s cars who we’ve treated in this manner every year or two since it was a few years old show no rust issues at the 10 year mark. I have one person who has a 2004 Ram 1500 which commonly rust out on the box above the rear wheel wells that was regularly treated in this manner. It shows NO signs of corrosion in these areas. As a bonus, the suspension is not corroded and is reasonable to work on as well.

  • avatar

    Get rid of it, it will be plenty more when you start looking! I’m living in the same conditions, in Sweden. All cars rust up sooner (Opel) or later (old Volvos). Unless… Get a new car or a used one without any signs of rust. Take it to a rust proofer, spray the underside with corrosion protection oil and drill holes in the doors and other cavities and spray. The worthless warranties against corrosion will be non valid. But it’s better with a car without warranty AND without rust. I take my car to a small independent shop and pay 100 usd every or every second year. Or you can go to the better shops (Dinol, Tectyl) and pay 1000 usd and it will be good for 5-10 years.

  • avatar

    Midwest 2008 Mazda CX-9 owner here: I’ve had very small rust bubbles on the rear hatch near the license plate holder for the past two years.
    I’ve been trying to hold it back by waxing the sh#t out of it – but the inevitable is hard to stop.

    Why is Mazda having so much trouble with rust?

  • avatar

    Some one needs to make this joke and I signed on explicitly to do so:

    Imagine how bad the next Miata will be after the Alfa team up.

  • avatar

    It really blows my mind people will pay 3-40k for a vehicle and not get it krowned or rustrproofed for 100 bucks per year if they’re going to drive in salt.

  • avatar

    I had a 2006 3 hatch bought new and driven for 5 years in NYC, I don’t remember any rust at all.
    Now, driving a 2011 3 hatch and also, can’t see any rust.

  • avatar

    I live in NYC where they use salt after every snow storm. After every snow storm as soon as the streets are clean i hose down the under part of any car i used. In 30 years of VW ownership i have never had any rust on any of my VW’s. Much to my surprise my 1991 Miata is still rust free and solid as a rock. Of course my wife’s 1986 Subaru was a pile of rust after 8 years. And this was a car that was rustproofed and guaranteed by the dealer for 10 years but of course the dealer went out of business in 7 years.Noticed the same thing on 2000 thru 2003 Outbacks.Funny thing on my VW’s during the hot summer season i sometimes have a slight wax film collecting in the door frames. It seems every summer the wax flows deeper and deeper into the body. Might work for Mazda.

    • 0 avatar

      The amount and frequency of salt used in NYC and the surrounding areas is a far cry from what is used in real snow states. My Sable finally got some rust perforation by the right rear wheel…after its 20th birthday.

      • 0 avatar


        Having to dry-wipe salt off an opaque windshield because it’s too cold to use fluid on ambient temp glass isn’t an unusual event in northern WI. Cars coated white from rockers to windows and weather too cold for car washes is the usual January scenario.

        Funny thing about that salt coating…it seems to have become really greasy with the switch to alternate formulations of road salt. It’s hell to get rid of the sheeny film even with my usual wet towel/dry towel technique and highly diluted Tide.

    • 0 avatar

      Subarus rust to bits in Ohio too, long before other cars (aside from Mazda) have that sort of problem. Always at the rear wheel wells and around the tailgate where water goes.

  • avatar

    most dealer rustproofing is inferior to krown and rustcheck

  • avatar

    Here in Cleveland, Ohio I can tell you that this issue is not fixed , the roads are salted from damn near six months of the year the mazdas are always the first to rust.

  • avatar

    i have some rust-related experience on older cars, in the recent years there has been a huge improvement. so this article is very interesting for me.
    the problem with rust is that it usually is much more serious than it looks and, obviously, “rust never sleeps”.
    when rust is on structural parts it gets very expensive/difficoult to repair it, rust on the body panels isn’t a big deal.
    so i’d say that if inspection shows that the floor/pillars are intact it’d be better to repair the mazda.

    when rust becomes structural it is a work for specialist only and sometimes the amount of welding necessary is so much that the car is unreparable. that’s the reason why old cars disappeared, the repair would be simply non sense.
    i remember working on a renault 16, basically rebuilding it from 0. very difficoult to avoid bending the bodyshell.
    but a rotten fender or on the outher face of the floor beam isn’t a problem.
    on modern cars i saw rust only on poor repairs. and some modern anti-rust treatment are bulletproof (i used dynitroll smells terribly but works).

  • avatar

    I noticed some traces of rust bleeding down the edges of the rear fenders on my ’04 Mazda3 a few years ago. Since then, I’ve been cleaning out the fender lip and spraying it down with Rust Check every spring and fall during the seasonal tire change. It seems to be effective, as I haven’t seen any rust there since. I also spray some into the doors through the drain holes.

  • avatar

    My daily driver ’05 3 sport GT hatch is rusting pretty badly on both rear fender wells, under the right reverse light, and under the Mazda badge on the left side of the hatch.

    It’s too far gone now to be worth anything so I’m gonna drive it into the ground (152,000km now).

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