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Discussion Starter · #1 ·
Hi All,

I had the front subframe replaced in my 2011 Mazda 6, through the recall.
My mechanic now says the same level of corrosion appears in the rear subframe. I didn't have the chance to go under it myself and take pictures, but the thought is very disturbing.
Does anybody else have the same problem?

Thanks.
Hakan Toykoc
 

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It seems to me that Mazda has used the cheapest of the cheap, ineffective paint on the subframes... or the process is wrong and incomplete... maybe not well-primed, not well-adhered, and not capable of resisting edge-corrosion. That is disturbing. Also, it seems also that some types of steel tend to corrode much more vigorously and completely than other kinds of steel. I often find this has occurred on Mercedes Benz cars, of a certain age. To be sure, the latter tend to be well-rustproofed.... but occasionally you see total rust-bucket Benzes.??? Don't know what is happening there - or here...

I wonder how the third generation Mazda6's are.
 

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Discussion Starter · #3 ·
Yes, I think it is bad quality issue no matter the reason. The mechanic at the Mazda dealer had told me when they were replacing the front subframe, that there was an AC line that could keep dripping on that particular spot on the subframe, causing corrosion. And that it would happen on the front right side of the car.

I didn't think much about it back then since I thought the issue was resolved. But the more I ask around, now my mechanic says they had lots of them with the issue on both sides at front. So the AC line story must be BS. Also, irregardless of a leakage onto the metal, it should be able to protect itself from corrosion right?
 

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1) it needs a proper paint system (decent prime-coat + good, thick-enough top-coat); and 2) when (not if) the paint system fails in a few spots - the base steel conponent has to be able to rust only insignificantly... not go "nuts" with layers of rusty steel spalling-off. In other words the purity and the base quality of the steel and the weldments has to be good. Obviously it has NOT been good.
 

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Discussion Starter · #5 ·
Does anybody else have rear subframe corrosion problem, Mazda 6 2009-2012?
It would be great if we all could raise voice and reach Mazda to see if they'd consider a follow-up recall for the rear subframe.
Anyone?
 

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Does anybody else have rear subframe corrosion problem, Mazda 6 2009-2012?
It would be great if we all could raise voice and reach Mazda to see if they'd consider a follow-up recall for the rear subframe.
Anyone?
I live on the east coast of Canada where we have a lot of salt on our roads. I have seen this problem on several Mazda 6’s and many end up in scrap yards prematurely because of this exact problem. It is important that you contact Transport Canada or the NHTSA if you’re experiencing excessive rust, flaking or a rear subframe failure, because this is a serious safety issue that needs to be addressed by Mazda and recalled like the front subframe. The subframes were improperly rust proofed and the metal used literally comes off in chunks. In this case, the lower control arm and spring may separate from subframe on an otherwise clean car with very little rust. This failure will cause a loss of control and make the vehicle unusable . Here are some pictures from a 2010 Mazda 6 2.5:

Wood Auto part Rust
Rust Wood
Tire Automotive tire Auto part Automotive wheel system Wheel
 

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wow. that's quite severe. It seem like some factory hot dipped their chassis and structural component while others do not..

currious but where was your vehicle made? which plant? maybe a connection?
 

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wow. that's quite severe. It seem like some factory hot dipped their chassis and structural component while others do not..

currious but where was your vehicle made? which plant? maybe a connection?
It was built in Flat Rock, Michigan (Ford plant) back when Mazda and Ford had a partnership. Correct me if I’m wrong, but I think all second gen North American Mazda 6’s and Ford Fusions were built there. It’s the road salt that really affects these cars’ subframes, so only the cars in the “rust belt” (Northeast) have these problems. Several people in the UK (salt+lots of rain) have had this problem as well according to my research on forums.
 

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The other question aside from the rustproofing is where was the steel sourced from (and what is the steel chemistry) and where were these subframes mfr'd?
 

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The other question aside from the rustproofing is where was the steel sourced from (and what is the steel chemistry) and where were these subframes mfr'd?
Well the chemistry of the steel and the manufacturing process of the subframes must’ve been really bad, because I’ve never seen a car’s subframe flake and disintegrate like this. It looks like it was left at the bottom of the ocean for a thousand years.
For example our other car of similar age (2011 Hyundai Elantra Touring) has never been rust proofed while exposed to the same conditions and this is what it looks like after 160 000km. A little bit of surface rust which is completely normal, but no severe corrosion or flaking.
239945
 

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Quality has changed over the years it seem.

I have an '03 and was also built at Flat Rock by AAI. It also has to deal w/yearly heavy snow and harsh road salt environment. It certainly hasn't crumbled. Some surface rust, yes. But nothing but a light sanding and prep/paint won't fix ..

૮( ᵒ̌ૢཪᵒ̌ૢ )ა
 

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Again, I'll bet there is some fundamental difference that certainly I don't know about at this time. Mazda subframes and pressed steel susp. components worry me 😐
 

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Quality has changed over the years it seem.

I have an '03 and was also built at Flat Rock by AAI. It also has to deal w/yearly heavy snow and harsh road salt environment. It certainly hasn't crumbled. Some surface rust, yes. But nothing but a light sanding and prep/paint won't fix ..

૮( ᵒ̌ૢཪᵒ̌ૢ )ა
An ‘03 is the first gen so the suspension and subframes are different. When they came out with the second gen, they must’ve changed their manufacturing techniques (read here cost cutting) which resulted in this severe rusting. It is as if moisture got trapped between layers of metal/paint, which causes this flaking, leading to a terminal failure.
239950
 

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I wonder if the 2nd gen and newer had the rubberized underbody coatings.. those are the worst. It traps moisture and doesn’t allow the metal to air out and will accelerate the corrosion.


So what’s the plan on this?

I think maybe if keeping the vehicle, get a cheap donor chassis — cut, transplant and weld new structures. Add some additional reinforcements and properly treat it to prevent future corrosion.

Interested in what Mazda may say, though..



(╭☞ ಠ ͜つ ಠ )╭☞ r=1+sinθ
 

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Let's hope Mazda does something about it. My 2nd gen had the front subframe "cancer"...


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Discussion Starter · #16 ·
I contacted Mazda about a month ago about my bad looking rear subframe. They simply said, no recalls for the rear one at this time. Deal with it and if a recall comes up, you would be reimbursed.
But I don't have the luxury to wait until they make up their minds. It is too serious a risk!

I looked up contact information to see if I can reach Mazda Japan directly with no luck. Does anybody know a way to reach Mazda Japan? An email address maybe?
 

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Uhh what? @Mz6GreyGhost wasn't there specifically a subframe recall that came out because of this crap? I thought you had yours done before upgrading to the 3rd gen.

Regardless, that's horrible corrosion.
 

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Yes, but only covering the front subframe, not the rear one.


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That's incredibly annoying and stupid.
 

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Are they weighing risk... that at least with the frt subframe being rotten steering control will be immediately lost if it structurally breaks-up. Not saying it won't affect strg (never mind brakes) if the rear breaks-up but I'll bet there is a risk calculus going on there...
 
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