Mazda3 owners with corrosion issues, join us here!

[ZoomZoom Girl]

I didn't noticed anything on my car last summer either - two times during the summer I wash my car by hand, thoroughly check out the body and touch up the paint.
Another change for me was that the Mazda spent most of the last winter outside. First two winters she spent the night in the garage and the day in a covered parking; this may be a factor too.

Mine started with the bottom trim of the rear passenger doors and the rear wheel wells about 2 years ago (yes, mentioned to dealership to no avail).  The rear quarter panels, rear bumper seams, and bubbling started last year. 

My car is never garaged.  I don't think there would be anything from an ownership perspective that could have stopped the corrosion if it is a defect of the body sheet metal.  I hand wash weekly in the warmer months so have been aware of any minute changes to the outer body since I got the car in June 2004....

Curious to hear what others think my core issue is, now that the pictures are up....

[PJungnitsch]

Even if chipped the primer should suppress rust and not lift off in a big pattern like that, not for a long time anyway. My '87 Mazda B2000 is covered in stone chips that go down to metal (spent prob 200,000 km on gravel) and the rust spreading under, and lifting the paint, has been a very slow process, as the primer sticks hard to the metal.

What % of the car has bubbling?

[ZoomZoom Girl]

Even if chipped the primer should suppress rust and not lift off in a big pattern like that, not for a long time anyway. My '87 Mazda B2000 is covered in stone chips that go down to metal (spent prob 200,000 km on gravel) and the rust spreading under, and lifting the paint, has been a very slow process, as the primer sticks hard to the metal.

What % of the car has bubbling?

Oh I'm awful at guessing numbers but can tell you that there are two large blisters on the driver-side front quarter panel, too many to count on the lower part of the driver door (below the side trim...not sure what that is called), also a sizable number on the lower part of the driver-side rear passenger door, 3 blisters on the driver-side rear quarter panel, 2 blisters on the top part of the passenger-side rear door, and about 4 blister on the lower part of the passenger-side front door.  Aside from those, the bottom of the car (which you see when you open the doors...not the side skirts) also has blisters at all 4 doors. 

[carcrazy]

Now that I looked at it closely, I think the problem around the wheel well - common to all Mazda3s, is because the plastic cover inside the wheel is not flash with the end of the rocker panel, therefore allowing the slush mixed with salt to collect and settle inside the wheel well, on top of the rocker panel (2-3 inches) and behind the rear quarter panel lip. It’s needless to say that the metal in that area is not painted - it's just the bare metal sheet (grey). Unless you spray that area with whatever rustproof material or make sure that you constantly clean up the slush (crazy), you cannot escape the rust and sooner or later it will pop-up.

[mrthompson]

Sorry for your paint and corrosion problems.  If your car was a 2006 or 2007 model I would have suspected that it had been salvaged from the Cougar Ace cargo ship.

http://www.usatoday.com/money/world/2006-08-03-cargo-problems-usat_x.htm

[ZoomZoom Girl]

Now that I looked at it closely, I think the problem around the wheel well - common to all Mazda3s, is because the plastic cover inside the wheel is not flash with the end of the rocker panel, therefore allowing the slush mixed with salt to collect and settle inside the wheel well, on top of the rocker panel and behind the rear quarter panel lip. It’s needless to say that the metal in that area is not painted - it's just the bare metal sheet (grey). Unless you spray that area with whatever rustproof material or make sure that you constantly clean up the slush (crazy), you cannot escape the rust and sooner or later it will pop-up.

I can kind of understand the rusting around the wheel wells and at the bottom of the rear passenger doors.  Those areas get blasted with road debris and the design of the wheel wells is bound to result in rusting.  Note that in 2005, Mazda began adding 3M protective tape over the bottom trim of the rear doors, obviously since they clued in that this was a problem area.  I THINK that they also began to 3M the rear wheel wells though I can't confirm that.

My main issue is the bubbling affecting most panels on my car.  Most are smooth with no impact points from rocks.  I have no solid proof as to the cause of that problem although a defect in the sheet metal is the most common explanation...

[ZoomZoom Girl]

Sorry for your paint and corrosion problems.  If your car was a 2006 or 2007 model I would have suspected that it had been salvaged from the Cougar Ace cargo ship.

http://www.usatoday.com/money/world/2006-08-03-cargo-problems-usat_x.htm

Well at least then I would KNOW what the root problem was, right?  Tragic really...

[carcrazy]

I can kind of understand the rusting around the wheel wells and at the bottom of the rear passenger doors.  Those areas get blasted with road debris and the design of the wheel wells is bound to result in rusting.  Note that in 2005, Mazda began adding 3M protective tape over the bottom trim of the rear doors, obviously since they clued in that this was a problem area.  I THINK that they also began to 3M the rear wheel wells though I can't confirm that.

My main issue is the bubbling affecting most panels on my car.  Most are smooth with no impact points from rocks.  I have no solid proof as to the cause of that problem although a defect in the sheet metal is the most common explanation...

Indeed, on my 05 (built Feb-05), there is a small clear film patch on the bottom of the rear door jam, where you have rust. I don’t see any obvious problems in that area (nor the bumper/fender seams).
Bubbling is a different issue and there is no doubt that it's a problem with the metal itself. It should be no problem to get that fixed by Mazda and depending on the body panels affected, get it replaced.
The biggest problem for me it's how the wheel well area can be fixed since that body part cannot be easily replaced. I’ll see how it goes with the dealer/Mazda, but if the worst come to worst I'll use some POR-15 product (or similar) before the winter starts.

[ZoomZoom Girl]

Indeed, on my 05 (built Feb-05), there is a small clear film patch on the bottom of the rear door jam, where you have rust. I don’t see any obvious problems in that area (nor the bumper/fender seams).
Bubbling is a different issue and there is no doubt that it's a problem with the metal itself. It should be no problem to get that fixed by Mazda and depending on the body panels affected, get it replaced.
The biggest problem for me it's how the wheel well area can be fixed since that body part cannot be easily replaced. I’ll see how it goes with the dealer/Mazda, but if the worst come to worst I'll use some POR-15 product (or similar) before the winter starts.

[/quote]

It is a poor design altogether.  I searched high and low for mudflaps to put on my car but none can be fitted due to the way the area is configured.  I really don't know what can be done, after the repair, to minimize future paint chipping and rust.

My paint bubbling, thus far, is on:  driver-side front quarter panel, all 4 passenger doors, both rear quarter panels, lower part of the car (when you open the door, what is at the bottom...not the outside side skirts).  So yes, they COULD replace my quarter panels and the doors which would resolve the bubbling.  Well, unless the replacements also have the "problem" metal.  No guarantees I guess.  That would be the ideal resolution since any danger of further corrosion spread would be eliminated.  Needless to say, I'm not holding my breath that Mazda Canada would agree to follow this procedure...

[initial_D]

I have a 10 year old Mazda Millenia, the rear wheel wells are getting really bad rust spots. Was going to repair them, but at over $1500, not really worth it.

[carcrazy]

I have a 10 year old Mazda Millenia, the rear wheel wells are getting really bad rust spots. Was going to repair them, but at over $1500, not really worth it.

I would expect to see rust after 10 years, but 3-4 years is too early. What bothers me is that this issue could've been prevented at no cost - just make the plastic cover inside the wheel well to close off the space so the mixture of slush and salt can't settle on the metal. I'm 100% sure that this is what caused the premature rusting on that area.

[ZoomZoom Girl]

I would expect to see rust after 10 years, but 3-4 years is too early. What bothers me is that this issue could've been prevented at no cost - just make the plastic cover inside the wheel well to close off the space so the mixture of slush and salt can't settle on the metal. I'm 100% sure that this is what caused the premature rusting on that area.
[/quote]

That's one thing.  Mazda Canada obviously DID know that the bottom trim by the rear passenger doors was very susceptible to damage since they began adding 3M protective coating in 2005!  I'm not sure about the wheel wells.  Perhaps someone with a 2005 or more recent year Mazda3 can check?  Is there tape over the rear wheel wells too? 

[carcrazy]

The small 3M clear film patch is only on the lower rear door jam. The clear film protects against paint chips thrown by the front wheels. The problem in the wheel well is due to a different cause and the clear film would not help at all. The rust is coming from the inner side of the rear quarter panel and rocker panel.
No, there is no other place protected with clear film on any model year.

[ZoomZoom Girl]

The small 3M clear film patch is only on the lower rear door jam. The clear film protects against paint chips thrown by the front wheels. The problem in the wheel well is due to a different cause and the clear film would not help at all. The rust is coming from the inner side of the rear quarter panel and rocker panel.
No, there is no other place protected with clear film on any model year.

Thanks for clarifying!

[carcrazy]

One more thing, the only way I can see to protect the wheel well from rust is to have it thoroughly sprayed with the rust proof material (tar?) from day one. In my case, it wasn't, although most of the wheel well was sprayed. This is way I hope I'll get this fixed by the dealer under the rust proof protection insurance.
This issue prompts me to closely examine the rest of the car as well as my other car, which had been sprayed from new as well.

[sixer]

The problems your having are as result of Mazda Developing the World's First Environmentally Friendly Coating Technology back in 02.

The Protege5's were the first to get it, thus resulting in thinner paint and rusting issues.  Obviously Mazda 3's are suffering as well.

Mazda has successfully developed a new environmentally friendly coating technology. It reduces the emission of volatile organic compounds (VOC) to the same level of VOC regulation in Europe where waterborne paints are mainly used, while achieving reduction of CO2 discharge and better coating quality. This significant technology has been launched at its Hofu Plant 1 in Yamaguchi Prefecture. The new technology is called "Three Layer Wet Paint System." Primer coating process is combined into the top coating process aiming to reduce environmental impact comprehensively.

The introduction of the new technology has achieved the following benefits:

1. Integrated process: Primer coating process is combined into the top coating process. This has contributed to a reduction in energy consumption by 15% CO2 discharge.

2. Emission reduction: Newly-developed low-solvent paint and reduced paint consumption through an introduction of high-efficiency coating robots have enabled Mazda to reduce emissions of VOC, such as toluene and xylene from the paint shop by approximately 45%.

3. Standard quality: Equal to that of current coating technology, through all-new interface control resin.

[Summary of new technology]

1. World's first Three Layer Wet Paint System

The Three Layer Wet Paint System is a system that primer coating process is combined into the top coating process. Primer, base coat and clear coat are applied continuously and baked all layers at once in the top coating process. The Three Layer Wet Paint System has been applied for the bottom of two-tone body, but not for the full body. Mazda is the world's first manufacturer that applies this new technology to the full body. The integrated process enables energy reduction, which was consumed in large scale within the paint booth and oven.


2. Newly developed paint to make Three Layer Wet Paint System possible

Mazda jointly developed new low solvent paint with lower VOC emission levels in cooperation with paint makers for the application of primer, base coat, and clear coat. Previously the surface of the primer and the base coat paints was separated by baking. In this new technology, a newly developed interface control resin separates the two coats. This resin is uniformly dispersed in the primer. Soon after the primer is applied, the resin moves to the surface of the primer, due to different surface tension, creating a high-viscosity barrier between the primer and the base coats.

3. Development of a highly-integrated/highly-efficient new coating system

Mazda has developed its own unique coating system that maximizes coating efficiency. Introducing more enhanced robots than the previous one, Mazda developed a system to control paint flow and air pressure with high accuracy. As a result, the number of coating robots required for each body has been reduced by 25%, and the primer application process has been integrated into the top coating process without extending the topcoat process. In addition, the robots have improved coating efficiency to reduce paint consumption, realizing homogeneous paint thickness and more uniformed quality.

In an effort to comply with the PRTR,* manufacturers are striving to develop environmentally sound technology. For example, with the aim of reducing VOC emissions, an increasing number of manufacturers are introducing a special coating process employing waterborne paints. Mazda, still using solvent paint, has achieved to meet the VOC regulation (35g/m2) of European countries where many companies employ waterborne paints. Furthermore, Mazda has drastically reduced CO2 emissions, as well as cutting down coating cost. This technology is expected as a comprehensive environmentally friendly measure.


Mazda is planning to introduce this technology at other plants, developing a further advanced method to employ waterborne paints to this system, aiming to further reduce CO2 and VOC.

*The PRTR (Pollutants Release and Transfer Register) is the system consists of "an arrangement for the registration and publication of the volume of harmful chemical substances released into the environment and the volume of such substances transferred as components of waste." Based on "The Law Concerning Reporting, etc. of Releases to the Environment of Specific Chemical Substances and Promoting Improvements in Their Management," it requires reports and publication of figures regarding chemical substances released into the atmosphere, water, and soil, and the volume transferred as components of waste.

[PJungnitsch]

So that's why it looks like the primer isn't working, there isn't any!

Basically they are trying to get away with not using a separate primer, using the all in one 'Tremclad' approach. The owners were guinea pigs to see if this system held up over time.

[gosteelerz]

I had a look at all the '04s at the dealer.  There were about 5 in total.  Three of them had minor paint blister in the rear driver's side wheel lip, ahead of the rear wheel.  None of them had any signs of corrosion anywhere else.  Two showed no signs of anything.

A possible preventative solution would actually come from a Honda.  The 5th gen Civic and maybe the 6th gen had rubber liners that covered this lip which should fit on the 3 as well.  I used to periodically remove them and spray some Krown in the groove and put it back on.  This would protect the most vulnerable part of your car and prevent any onset if you get it early.

[onearmed]

Do they galvanize(sp?) their metal?  I know Audi,VW,mercedes,bmw do and I don't see or hear of rust anymore with those cars unless they've been in an accident.  If they don't, maybe they should pony up some more cash to do this.

[IceAndFire]

I think only the makes you mentioned use galvanized steel.  I had heard of some VW's rusting prematurely...but maybe I'm remembering wrong.  Seems like no car is completely safe from rust no matter what.