Koni FSD strut failure

While driving to the store today, I heard a large clunk, a burning rubber smell started to fill the cabin and a cachunk-cachunk noise kept getting louder and louder. I pulled over to a side street as quickly and safely as possible and found this.


Luckily, I wasn't too far from home. After making it back and pulling the wheel off, I found this as the cause.



The FSD's have been on my car for over 10yrs through MN winters, but I wouldn't think this should happen. Has anyone else experienced anything like this before?

Pretty sure there have been Koni bucket failures due to rust.
You're in MN, they use salt, and you haven't changed your sus in over 10 years. I'm not surprised.
I've never let my suspension go that long before and I've never been in a rust belt. After 10+ years I bet those struts were already shot.

Not sure how many miles you had on those Konis but honestly I'd say they lasted pretty long time in rust belt. Which reminds me, I need to check my struts... Damn you salt.

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This is why I love my Bilsteins in Maine.

The cup can hold dirt and grit, and of course that will be saturated with road salt :-(

I suppose basting the cups out with a hose in the spring each year should be added to the maintenance list.

I don't think Koni is making the FSD for the mk4 cars anymore, a friend got some a little while back and had a really hard time finding them in stock anywhere.

You can call Koni and see if they'll warranty it. You do need to provide current registration and insurance. I had some Koni reds go bad on my 2003 sprinter, and warranty replacement was somewhat of a hassle, but to get $600 of struts for free it was well worth it.

"I don't think Koni is making the FSD for the mk4 cars anymore,"

https://www.idparts.com/koni-special-active-strut-and-shock-set-a4-p-561.html

Now they're called "special active", and red instead of yellow, and cheaper.

Rrusse11 said:

"I don't think Koni is making the FSD for the mk4 cars anymore,"

https://www.idparts.com/koni-special-active-strut-and-shock-set-a4-p-561.html

Now they're called "special active", and red instead of yellow, and cheaper.

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Awesome! Thanks for the info!

The left front spring on my Golf broke where it rests on the Bilstein perch; most likely from salt. I undercoated the bottom of the perches, and plan on spraying some WD40 on the perch itself.

I sent Koni warranty support an email w/ the pictures from above. The car is my daily driver so it has current registration and insurance but I can't find my purchase receipt so hopefully they are forgiving. I guess we'll see.

Given I can't wait for the warranty claim to come through, I purchased a set of Bilstein B4 OE's for the front. The rear Koni shocks are still doing ok, so I wasn't planning on replacing those, unless someone thinks my car will ride funny with the unmatched set.

ottoman said:

I sent Koni warranty support an email w/ the pictures from above. The car is my daily driver so it has current registration and insurance but I can't find my purchase receipt so hopefully they are forgiving. I guess we'll see.

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Did you buy them online?

I searched my emails and found the purchase confirmation email for my Koni's and I screenshotted that and sent it to them.

JB05 said:

The left front spring on my Golf broke where it rests on the Bilstein perch; most likely from salt. I undercoated the bottom of the perches, and plan on spraying some WD40 on the perch itself.

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WD isn't going to do jack for protecting. I would honestly use something like FluidFilm.

ottoman said:

I sent Koni warranty support an email w/ the pictures from above. The car is my daily driver so it has current registration and insurance but I can't find my purchase receipt so hopefully they are forgiving. I guess we'll see.

Given I can't wait for the warranty claim to come through, I purchased a set of Bilstein B4 OE's for the front. The rear Koni shocks are still doing ok, so I wasn't planning on replacing those, unless someone thinks my car will ride funny with the unmatched set.

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I'm going to reiterate... Your suspension is over 10 years old and have been subjected to a really harsh environment... The rears are likely just as bad off as the front. Do yourself a favor and just refresh the entire sus including the rear mounts.

After seeing the front I don't think anyone would recommend to you to "just keep driving" on that until they fail. It's your handling and others safety around you at risk when you neglect things like this

I received a reply from Koni Customer Service today:

Hello Nik,
I am very sorry to see the severe rust issue on your KONI FSD shocks and struts on your Jetta. I definitely think we need tom address this issue through our warranty process. Please use the below links to our website and they will help you prepare and submit the Warranty information and then we can get a Warranty Claim in process.
https://www.koni-na.com/en-US/NorthAmerica/About/Warranty/ Warranty outline
https://www.koni-na.com/CorporateSite/media/itt/pdf/36732_KONI_Warranty_HowToObtain.pdf Process explanation
https://www.koni-na.com/CorporateSite/media/itt/NA/pdf/35331_KONI_Warranty_Form_Temp.pdf Submission form
Best regards,
Lee Grimes
Automotive Product Manager
KONI – an ITT company

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So I'm hopeful something will come of this. I'll keep posting updates as they come.

Customer of ours had the same problem. Car was parked a lot of thhe time (outside in MA and VT) and he had the same failure. I had FSDs on my Wagon for 7 years and they didn't look anything like that. The Reds on my cars are 6 years old and look pretty much new. I wash the car a lot, however, especially during winter.

Lee Grimes will take care of you if he can.

Koni is crap. Not the worst but not that great either. If I was you I would spray some chainsaw bar oil on them before winter hits. Old trick works great in a spray bottle

IndigoBlueWagon said:

Customer of ours had the same problem. Car was parked a lot of thhe time (outside in MA and VT) and he had the same failure. I had FSDs on my Wagon for 7 years and they didn't look anything like that. The Reds on my cars are 6 years old and look pretty much new. I wash the car a lot, however, especially during winter.

Lee Grimes will take care of you if he can.

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You were exactly right, Lee is excellent to work with! He gave me a call and walked me through the process. After sending in all the info, they agreed to send me a new set of Koni Special ACTIVE's for my car. Not just for the front but all 4 corners! They're currently back-ordered but should be here in a few weeks.

ottoman said:

You were exactly right, Lee is excellent to work with! He gave me a call and walked me through the process. After sending in all the info, they agreed to send me a new set of Koni Special ACTIVE's for my car. Not just for the front but all 4 corners! They're currently back-ordered but should be here in a few weeks.

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Did your process match either Koni warranty option 1 or 2? It sounds like you are getting replacements after only sending in paperwork/pictures? Mine are also rusted out, but I can neither lose the down time of removing and waiting, nor happy about buying a set in advance without certainty of full warranty.

This cant be all of the sudden. You didnt notice it sagging or something off with the tire wear before it failed?
This isnt a over the weekend new issue.

hskrdu said:

Did your process match either Koni warranty option 1 or 2? It sounds like you are getting replacements after only sending in paperwork/pictures? Mine are also rusted out, but I can neither lose the down time of removing and waiting, nor happy about buying a set in advance without certainty of full warranty.

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I opted for Option 2. Yes, I sent them an email with the photos above and paperwork. I could have opted to receive a set of Koni Sports (yellow) which they have in stock but I don't think I'd like the firmer ride. My Jetta is my daily driver but I'm fortunate that my wife and I can carpool while my car sits in the garage awaiting the replacements.

ottoman said:

I opted for Option 2. Yes, I sent them an email with the photos above and paperwork. I could have opted to receive a set of Koni Sports (yellow) which they have in stock but I don't think I'd like the firmer ride. My Jetta is my daily driver but I'm fortunate that my wife and I can carpool while my car sits in the garage awaiting the replacements.

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Sorry otto, just to clarify so I know what to expect...

The photos played what role?

When you said "After sending in all the info, they agreed to send me a new set of Koni Special ACTIVE's for my car" does this include sending your shocks and struts back prior to Koni agreeing to send free replacements?

Definitely a good thread for me to remember...
I had read some posts we're supposedly konis don't have good rust protection ( but hopefully that's changed by now).

For what it's worth I think you'll like the special actives it's what I have currently on my car.

Mongler98 said:

This cant be all of the sudden. You didn't notice it sagging or something off with the tire wear before it failed?
This isnt a over the weekend new issue.

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I certainly had noticed the rust a while ago but never thought it would cause this to happen. I wash my car regularly and so far have kept all rust at bay on the rest of the car, including undercarriage (except for the lower hatch lip, common manufacturer defect). The front driver's side has been making a clunking noise going over very large bumps for a few months so I planned on rebuilding the suspension this spring to correct that. An alignment was performed just a few weeks ago after I replaced the front outer tie rod ends and the shop said tire wear looked very even.

It's an old car. Handling certainly doesn't have that new-car feel. But did it feel squishy, slow or problematic? Definitely not.

The strut cup failure was immediately noticeable. It broke off and the spring pushed down into the tire. The damper itself is still intact and working well so prior to it breaking, nothing really seemed off.

hskrdu said:

Sorry otto, just to clarify so I know what to expect...
The photos played what role?
When you said "After sending in all the info, they agreed to send me a new set of Koni Special ACTIVE's for my car" does this include sending your shocks and struts back prior to Koni agreeing to send free replacements?

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No worries, I'll clarify.
I initially emailed the photos to warranty@koni-na.com. They contacted me saying that's definitely a problem and walked me through the warranty process. I sent them:

1. Active registration for my car
2. Original purchase receipt
3. Warranty claim doc filled out

They confirmed receipt within a few hours and asked which model I wanted as replacement since the FSDs are no longer made. I opted for the Special ACTIVE's even though they are on backorder.

Had Koni yellows on a car several years back. Noticed an improvement in control and response but not a much harsher ride. FWIW.

rip that x-ice i3

ottoman said:

No worries, I'll clarify.
I initially emailed the photos to warranty@koni-na.com. They contacted me saying that's definitely a problem and walked me through the warranty process. I sent them:

1. Active registration for my car
2. Original purchase receipt
3. Warranty claim doc filled out

They confirmed receipt within a few hours and asked which model I wanted as replacement since the FSDs are no longer made. I opted for the Special ACTIVE's even though they are on backorder.

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Thanks for the info. So they accepted the warranty based on the pictures and steps 1-3 and will be sending new units free of charge? Or you paid for new FSDs at 50%, and are awaiting reimbursement after they receive and inspect your old units?

That's great news. How long did you have them before this happend or it started to rust out?

SledDawg2 said:

This is why I love my Bilsteins in Maine.

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I second this ^^^ all day long.
Been running billy sports since 90’s in New England salty roads, without issue.


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People like Bilstein and Koni, Koni are more prone to rust.

My bilsteins started rusting (only where the welds were) within the first 6 months to a year, but thats all its done other than be awesome.