As automotive journalists, we try to keep our finger on the pulse. What helps us even more is when our broad readership clues us in to what’s happening on the ground. Just this past week, I heard from John, who had read my piece on Jeep’s painful corrosion issues. He wrote in to let me know that the story goes deeper than just a single Stellantis brand.
John wrote in regarding his 2019 Chrysler Pacifica, which suffered a very similar issue to the Jeeps we’ve seen previously. “As you can see in the pictures, the paint on the hood was bubbling,” John told us. “I honestly don’t know when it started… maybe two years after I bought the car.”
What’s notable about John’s issue is that it comes down to one thing—aluminum. The Pacifica hood, like the Wrangler’s doors, is made of the lightweight material. Over the years, it’s been causing problems for Jeep, for Chrysler, and so many other brands—Stellantis and otherwise.
Flaky
The corrosion on John’s hood was quite unsightly. Bubbling occurred along much of the hood’s leading edge, with paint flaking off in places and leaving the metal exposed underneath. He also noted some paint flaking off the steel fenders, in the area hidden by the closed hood. Thankfully, he was able to get the ugly mess repaired, but not without some trouble.
“I was ultimately able to get the hood replaced under the factory corrosion warranty, but it was certainly a hassle,” he explains. He’d bought the car a ways away from his home in North Virginia, and that caused problems. “None of the dealers in the Northern Virginia area would touch the warranty work because I did not buy the car from them.”
Eventually, he was able to get the issue dealt with by the dealer that sold him the vehicle, over the border in Maryland. “The shop in Maryland, while inconvenient, did a nice job on the hood replacement,” he says. “The warranty wouldn’t touch the failed paint on the fenders.”
Was this just an oddball problem on John’s Pacifica? Well, he’s the investigative sort. He quickly found out that wasn’t the case. “I walked the parking lot during some downtime at my kid’s swim meet,” he explains. “I found six more Pacificas… five of them had the same corrosion on the aluminum hood.”
Anecdotal evidence from the dealership supported that theory. “The shop manager that I worked with said that this is a pretty common problem with Chryslers, apparently related to poor materials, cutting corners on prep, and working too fast,” says John. Plus, you can jump on just about any Chrysler forum, and you’ll find plenty of posts on the same topic.
Indeed, official documents stand testament to the widespread nature of the problem. Stellantis issued a Technical Service Bulletin in 2022 regarding “Aluminum Body Panel Corrosion Repair.” Under Vehicles Affected, you’ll find the Jeep Wrangler and Gladiator dating back to 2018, as well as the Chrysler Pacifica dating back to 2017.
Oh! But you’ll also find the Dodge Journey, Avenger, Dart, Challenger, Charger and Viper, dating back as early as 2013. Fiats, Alfa Romeos, and Ram pickups are implicated too. Basically, if it’s got an aluminum panel, Stellantis figured it could be affected.
The prime example seen on the TSB is the classic Jeep Wrangler hinge corrosion. The following example image shows it happening on the leading edge of a hood. Stellantis doesn’t outline a causative factor in the TSB. When we discussed the Jeep matter with the automaker, it put it down to “occasional variation in the manufacturing process.” The problem can be repaired in two ways. The panels can be sanded, treated with an anti-corrosion pen, and refinished. Alternatively, the panels can be replaced entirely if the aluminum corrosion has badly pitted the surface.
It’s worth noting that not all of these vehicles are built in the same factory. That would be a compelling common factor if it were the case, but it’s not. The Chrysler Pacifica is built in Windsor Assembly in Ontario, Canada. Meanwhile, the Jeep Wrangler and Gladiator are built at the Toledo Assembly Complex in Ohio. To say nothing of all the other Fiats, Dodges, and other cars called out on the same Technical Service Bulletin.
Not Just Stellantis
Fundamentally, it seems like Stellantis has had long-standing issues with reliably painting aluminum panels. But it’s not the only one. Ford has faced these same struggles.
In a technical service bulletin released in 2020, Ford tackled the problem of “Aluminum Panel Corrosion.” It covered all Ford, Lincoln, and Mercury products dating back to 2000, though only some had extensive use of aluminum body panels. “Some 2000 and newer Ford, Lincoln, and Mercury vehicles equipped with aluminum body panels may exhibit corrosion concerns appearing as bubbled and/or peeling paint with or without accompanying white dust,” read the bulletin. “Panel replacement is recommended.”
In Ford’s case, we do have a rough idea of the cause. Going back all the way to 2004, an earlier TSB put the issue down to panels being contaminated with fine iron particles prior to painting. This caused galvanic corrosion thanks to the dissimilar metal reaction between the iron particles and the aluminum panel. This happened under the paint, causing bubbling and corrosion with ugly results. As read the bulletin:
BACKGROUND:
Ford’s Scientific Research Laboratory has performed a number of tests on vehicle body parts returned for corrosion related concerns. Testing has revealed that the aluminum corrosion was caused by iron particles working their way into the aluminum body part, prior to it being painted.
SERVICE TIPS AND PROCEDURE:
When repairing a vehicle for corrosion or collision damage, it is essential that extreme care be taken to cover and protect all aluminum parts to prevent cross metal contamination. Areas in a shop where metal work is performed should be sectioned off, using at the very least curtain walls, to prevent metal dust migration. Cross contamination can also occur through the use of metal working tools (hammers, dollys, picks, grinding wheels, etc.). Tools used for aluminum repairs should be kept separate, and not used to repair other metals. Wire brushes used on aluminum should be made of stainless steel.
Ford had initially requested that repairs be undertaken by sanding and repainting the affected panels. The whole matter eventually ended up in a lawsuit, and Ford switched to recommending outright panel replacements instead.
Ferrari, too, has faced this issue. Rather infamously, the F12 is known for showing this characteristic bubbling under the paint, much to the frustration of owners. As seen in this video from AutoVlog, the problem looks remarkably similar to the flaking seen on Jeep and Chrysler product.
Curiouser And Curiouser
The big question remains—what’s going on here? Why are so many automakers having trouble with aluminum corrosion? And just as interestingly, why is it affecting some automakers more than others? Google will give you plenty of examples of Ferraris, Fords, Chryslers, and Jeeps with these issues. Meanwhile, Chevrolet has used aluminum panels for quite some time now, but examples of aluminum corrosion on its products are much harder to find.
Ford’s research does provide a compelling explanation for the problem, at least for its own vehicles. At the same time, it’s a little confusing that in so many vehicles, the problem first shows up on the edges of the hood. You would perhaps expect external iron contamination to land in nearly-random spots on a body panel, rather than always on the hood’s leading edge.
Went see an Ecoboost and noticed this bubbling on the hood. The hood was not properly aligned. 2015 Ecoboost that lived in Michigan. Should I be concerned? I would like to buy it, but what if they had an accident and the did a crappy job at fixing it? Carfax says there was a minor accident.
byu/huirosco inMustang
One problem we have is that automakers aren’t altogether forthcoming about why they’re having these problems. Barring Ford’s example above, none have really come out and said “our aluminum panels are corroding and seeing paint bubbling because of this single factor.”
This is something I intend to get to the bottom of in due time. Paint experts must be consulted, and more automakers asked for their explanation of the problems out in the wild.
Overall, though, it’s worth noting that there’s nothing fundamentally problematic with aluminum. Plenty of vehicles seem to use it without widespread problems. The hood on the original Mazda Miata is a great example, not exactly known for paint bubbling issues. So there must be a way to get it right—and a way to get it wrong.
Ultimately, one thing remains obvious. If you’ve got the bubbling on any car, panel replacement seems the most surefire repair. May the warranty be with you.
Image credits: Chrysler, John P (supplied), AutoVlog via YouTube screenshot
I would bet a lot of money that the problem comes down to the tools and dies or other equipment used to form the metal panels. If they are steel or contain iron, I bet even a small amount of it rubbing off onto the formed aluminum panels would be enough to kickstart the corrosion process. Have you ever taken a steel can of canned soup or beans and rubbed or twisted the can on the bottom of your stainless steel sink? After you’ve rubbed it you can’t tell, but later you may find a ring of rust on your stainless steel sink, which you didn’t even think could rust. It’s from the few molecules of steel/iron that rubbed off of the bottom of the can. Ford admitted that a small amount of iron contaminate could kickstart the corrosion process, and I bet some of this contamination is coming from the tools and dies used to form the aluminum panels.
My first job as an engineer was as a Red X engineer at GM Powertrain, doing technical problem-solving. I read this and see it as a fun challenge to work on!
I’m going to go out on a limb here and make a broad guess. Decades of steel panels used by automakers leads to paint and primer that is formulated to bond well with that material. Switching to aluminum would seem to dictate the need for different formulations of primer/paint to prevent said corrosion from occurring.