2021 CX-5 Surface rust on lower control arm?

[Dark5tar]

I live in Auckland. New Zealand, a city that never snowed or had any salts applied to the road. I live in an urban city and never took my 2021 CX-5 off road, ever. It has had an easy life being driven on smooth asphalt roads and highway throughout my 2y of ownership since brand new. So far only driven 18k.

During my yearly inspection today, I was really surprised to find some surface rust on the passenger side lower control arm (we drive on the left with steering wheel on the right). This rust must have formed several months back, as I could see some pain black paint peeling off and more rust bubbles forming underneath. See photos attached. The last photo was taken from the driver side for comparison

I was quite taken by this, especially in such a low mileage and age. I know Mazda has a rust problem in the past, but this is a 2021 CX5 being driven in a city that never snowed!

Is this normal? I will be making a booking to Mazda to get this inspected under warranty for sure.

 

[Jack Rabbit]

I live in Auckland. New Zealand, a city that never snowed or had any salts applied to the road. I live in an urban city and never took my 2021 CX-5 off road, ever. It has had an easy life being driven on smooth asphalt roads and highway throughout my 2y of ownership since brand new. So far only driven 18k.

During my yearly inspection today, I was really surprised to find some surface rust on the passenger side lower control arm (we drive on the left with steering wheel on the right). This rust must have formed several months back, as I could see some pain black paint peeling off and more rust bubbles forming underneath. See photos attached.

I was quite taken by this, especially in such a low mileage and age. I know Mazda has a rust problem in the past, but this is a 2021 CX5 being driven in a city that never snowed!

Is this normal? I will be making a booking to Mazda to get this inspected under warranty for sure.

Just need to say that your city is beautiful with streets that are the cleanest I've ever seen.

As far as your rust...That is very possible but also very quick for that to have formed on the control arm.

As someone who has tested out rusting of materials, salt only accelerates rust. Metal will rust even submerged in distilled water.
Pull it out and air accelerates the rust process. Add salt and it rusts even faster.

As we are in the snow belt & drive salted roads here where I'm from, that is quite quick for that to have formed.

The surface rust on the bolts, etc looks normal as you live in a saltwater city so close to the ocean and inlets/bays. Saltwater air x 365 days a year.

However the control arm appears as if either:
1.The control arm had been sitting out at the factory and had some rust spots prior to paint application process. The rust continued rusting underneath, bubbled and peeled the paint, and your saltwater air accelerates the process.
2. You may have hit something(maybe scraped a curb) or something bounced up off the road and chipped the paint, rust formed and spread, peeling the paint . Your saltwater air accelerated the process.

Hopefully they'll replace under warranty, assuming it was defective from factory.

If not, coat it in fluid film to stop/slow/inhibit the rust process.
Since you live so close to the ocean, you may want to spray the whole underside with fluid film like we do here. Fluid film soaks into and penetrates into the rust/metal and hardens into a waxy coating. You can see pics of my wheel well with fluid film if you look at my thread "CX-5 Sleek and modest Off-road mods". See pic below

 

[Dark5tar]

Just need to say that your city is beautiful with streets that are the cleanest I've ever seen.

As far as your rust...That is very possible but also very quick for that to have formed on the control arm.

As someone who has tested out rusting of materials, salt only accelerates rust. Metal will rust even submerged in distilled water.
Pull it out and air accelerates the rust process. Add salt and it rusts even faster.

As we are in the snow belt & drive salted roads here where I'm from, that is quite quick for that to have formed.

The surface rust on the bolts, etc looks normal as you live in a saltwater city so close to the ocean and inlets/bays. Saltwater air x 365 days a year.

However the control arm appears as if either:
1.The control arm had been sitting out at the factory and had some rust spots prior to paint application process. The rust continued rusting underneath, bubbled and peeled the paint, and your saltwater air accelerates the process.
2. You may have hit something(maybe scraped a curb) or something bounced up off the road and chipped the paint, rust formed and spread, peeling the paint . Your saltwater air accelerated the process.

Hopefully they'll replace under warranty, assuming it was defective from factory.

If not, coat it in fluid film to stop/slow/inhibit the rust process.
Since you live so close to the ocean, you may want to spray the whole underside with fluid film like we do here. Fluid film soaks into and penetrates into the rust/metal and hardens into a waxy coating. You can see pics of my wheel well with fluid film if you look at my thread "CX-5 Sleek and modest Off-road mods".

Thanks for your reply. Our city got flooded yesterday (the worse ever recorded apparently). I drove through some flooded roads (not very deep and was the first time) which prompted me to check the under carriage. I just added a 4th photo of the driver’s side. I could see minor rust spots starting to form as well, so it’s definitely a case to take up with Mazda.

I’m hoping they’ll fix under warranty. If not, or if they charge too much, I might take your advice and sand the rust out myself then apply an enamel rust inhibitor like this to it. SCA Metal Cover Enamel Rust Paint Matt Black - 300g

 

[Jack Rabbit]

Thanks for your reply. Our city got flooded yesterday (the worse ever recorded apparently). I drove through some flooded roads (not very deep and was the first time) which prompted me to check the under carriage. I just added a 4th photo of the driver’s side. I could see minor rust spots starting to form as well, so it’s definitely a case to take up with Mazda.

I’m hoping they’ll fix under warranty. If not, or if they charge too much, I might take your advice and sand the rust out myself then apply an enamel rust inhibitor like this to it. SCA Metal Cover Enamel Rust Paint Matt Black - 300g

Just be aware:

Paint type rust inhibitor- you need to get all the rust off or your back to the same thing. rust will continue spreading underneath the new paint inhibitor and peel again.

Rust Converter - these were found to convert rust to a inert material but eventually it flakes off and leaves bare metal exposed and rusting

Fluid film/Krown - there is debate as to which one of these is better but they are all better alternatives to the above options. Fluid film coats and penetrates the rust to stop it from rusting further. Same with Krown. And a bonus, you can sand , but dont need to as fluid film actually seeps into the rust,

 

[Buzzman12]

That's common here in snowy Canada, salty winter roads, etc., but even here, to see that must rust on a 2021 is cause for concern. It was probably already rusting when installed in the factory. The part could have been sitting around in the factory for months, if not years.
I'd definitely go back to the dealer and complain. Then get the undercarriage oil sprayed.

 

[RedBaron]

Even if they dispute your claim, I wouldn't worry too much about it. I doubt it will progress much to the point where it would be a safety issue (at least before the knuckle wears out and you have to replace them anyway! ). By all means spray them as mentioned above, though.

 

[Dark5tar]

Even if they dispute your claim, I wouldn't worry too much about it. I doubt it will progress much to the point where it would be a safety issue (at least before the knuckle wears out and you have to replace them anyway! ). By all means spray them as mentioned above, though.

I would want to brush off the rust and apply an anti corrosion paint on it at a minimum. Seeing it rusting away like this on a 2y old car just doesn’t cut it for me.

 

[Sel]

I live in Auckland. New Zealand, a city that never snowed or had any salts applied to the road. I live in an urban city and never took my 2021 CX-5 off road, ever. It has had an easy life being driven on smooth asphalt roads and highway throughout my 2y of ownership since brand new. So far only driven 18k.

During my yearly inspection today, I was really surprised to find some surface rust on the passenger side lower control arm (we drive on the left with steering wheel on the right). This rust must have formed several months back, as I could see some pain black paint peeling off and more rust bubbles forming underneath. See photos attached. The last photo was taken from the driver side for comparison

I was quite taken by this, especially in such a low mileage and age. I know Mazda has a rust problem in the past, but this is a 2021 CX5 being driven in a city that never snowed!

Is this normal? I will be making a booking to Mazda to get this inspected under warranty for sure.

I am also in Auckland and have a White 2020 Cx5 and have door arm rust spots too. First noticed them in 2022 and Mazda sprayed them with anti rust paint. I now have small rust spots on roof and bonnet. I don't live near the sea and never had issues with my Cx7. My husband's 2019 Cx9 also had the same issues with rust in the door arm and roof.