Hey MBW,I’m reaching out to the MBWorld community for some help and advice.

I’ve got a rare one in NA, a 2007 Mercedes-Benz S350 (W221) imported from Japan. I live in Canada, this model wasn’t sold here, so it’s been a bit of a headache finding accurate parts or even just getting basic info from local dealerships. The car doesn’t show up in their systems, and most North American parts websites don’t list the S350 trim.

Recently, there has been an issue with the airbag in the front right, which has caused the car to sag. Now it’s currently parked until I can sort it out. The previous owner in Japan had the car lowered, but I don’t know if that was done through the system or with aftermarket modifications. Because its lowered, I can't just replace the front two struts, I'd have to replace all 4.

At this point, I’m considering two options:

1. Replace all the air suspension components with this eBay kit: https://www.ebay.com/itm/33513899387...3BZ2DB97B3N9ZG
   
2. Convert the entire system to coilovers with an Arnott Coilover Conversion Kit: https://www.arnottindustries.com/blo...now-available/
   

A few concerns:

• Has anyone here driven or worked on an S350 with air suspension failure?
  
• If I buy air struts for the S500 (which is much easier to find here), will they fit my S350?
  
• Any compatibility issues I should be aware of with the coilover conversion kits?
  

I’d really appreciate any firsthand experiences or advice. The car has been great otherwise and I’d love to keep it on the road, but I want to make sure I’m not wasting money on something that won’t even fit.

Thanks in advance for the support.

Cheers,
Juzo

 

anyone that's ever sat in a W221 must have had that issue

 

Juzo - If you want my honest opinion, a large part of the beauty of a W221 is in the suspension. When it's working right of course, not when it has an air leak.
No other car, that I know of, can ride this smooth and handle this well on an air suspension. ABC is in another world entirely, and also works awesome, when it is working right.

Moving to an aftermarket spring strut suspension, rather than Air or ABC, will likely mess everything up. Read about others that have done so. I think you will see their honest opinion after conversion is a degraded car. I wouldn't do it.

What should you do?
I'm 99% certain the ride height can be recalibrated to the level you want by using the SDS, or simply adjusting the level sensors to the proper locations. I believe there are 3 sensors on the car.
Find a local independent shop and ask if the can "calibrate your suspension ride height using SDS". If they say yes, it's a done deal.

The struts themselves are likely the same for all W221 RWD, and similar for all W221 4Matic. Run a part number check for your model (assuming USA or Canada), then check older or more recent years. The struts are likely the same part number.
To confirm, jack a corner up on your car, pull the wheel, clean the strut really well, and read the part number. Almost all stock parts will have the part number on them. If they were replaced, all bets are off.

Then order a pair of struts you trust, and bolt them on. Or have your indy bolt them on. Some say Arnott are not what they used to be. Bilstein are still considered quality. Buyer beware.

Good luck, and let us know how it turns out.

 

May I suggest that you do the following:

1. Visit eBay.de
2. Order the parts from a used vehicle
3. Import them & pay the duty, it will be minimal
4. Install / end of story

I would venture to say that the S500 non-ABC airmatic struts will be the same.

I will find out, but I'm pretty sure they will be same, my only concern is the weight over the front axle, I would expect the S500 airmatics (front) to be calibrated for that extra weight.

FYI this is not a huge problem, please forgo and idea of replacing with coils.. BTW, glad you have an S350, the M272 is extremely fuel efficient, significantly easier on fuel than the V8's. Enjoy the car!

 

the world would be far happier if you share your drugs...

on the right,tyre & wheel combo, a smooth road and a tip top optional ABC suspension system many would be happy with the ride and handling balance

however if you have the far more common, standard fit airtragic suspension - its a sick unreliable joke, one of most uncomposed and incompetent disasters fitted to a motor car - its why they fitted17" wheels to the original cars to make it remotely bearable

for the OP as you'll find in multiple threads - the two front and single rear level sensors are likely seized and feeding faulty info back to the car - the $45 x 3 link rods will be snapped off or seized
the air pump half worn out
and the suspension strut airbags in each corner likely at end of life

all perfectly normal and std service items - air suspension keeps the manu in the game with nice levels of expenditure and regular opportunities to remind owners its time to upgrade - they get away with it as people that can afford to buy a new car are now a different type of gullible fool that couldn't feel the difference between a real car and a modern one

 

So, you have right hand steering wheel in Canada. Are you permanently in Canada with it? Canada allowed the right-hand driven car on the roads?

About the problem you have, if it is AirMatic, replace both front air struts as the other one will go soon too rears to follow. Unless struts were replaced less than seven or so years ago you might need to just replace the one leaking, just make sure you use the same part. For having the same parts on each side of the car it is best to replace both on the same axle.

If car was lowered it does not matter. Lowering was not done with the strut themselves. It was done either using the Xentry/DAS system or by some other system that changes the car's ZERO-level point or tampers with the level sensors. Car riding height is controlled with the level sensors signal and there is no need to touch them for strut change.

BOTUS mentions the sensor link as a possible problem and yeas, you would want to check that this is not the problem. Jack the car up and remove wheel. The sensor is located on the forward side of the top wishbone, and it has an arm connected to the "bone" with a link to read its position. This link can become disconnected and if that happens the car wil either go down or up depending on in what position the arm stops. It probably means cor goes down.

What comes to Arnott struts, I will not use them anymore. Their quality has gone so bad it is hit and miss if you have healthy part from them. They are about half price to Bilstein though that cost around $1250/piece when Arnotts are about the same for a pair at FCP Euro.

At RockAuto you can get Bilsteins for about $700 each, which is what I would go with if I was you, i.e., get two front Bilstein struts for about $1400 from RockAuto. I think they sell in Canada too.
If your car is RWD the part is the same on both sides but if it is AWD the parts are LEFT and RIGHT.

Do not ruin your car with coil overs!!!

 

OP before firing the parts cannon at it plug it into Xentry and see what it thinks of itself.

May just be a bad sensor or an arm popped off.

Nickel in a bet says that BenzNinja can help with some software for it too.

 

Try the ebay kit. Looks good.

 

Hi everyone,

Thanks so much for all your replies, I really appreciate the advice.

I'll definitely look into plugging it in somewhere to get a better idea of the issue. One challenge is that there aren’t many air suspension specialists here in Calgary, Canada. I think my best bet is to take it to a Mercedes dealership and hope their diagnostic systems can connect properly. (Though last time I went, they mentioned their system didn’t recognize my car since it’s a Japanese import and likely has different language settings or some sort of connectivity issue.)

I’ve decided to scrap the coilover idea. From what I’ve gathered, the air suspension components from an S500 should likely fit, so that’s my worst-case scenario if it comes down to replacing parts out of pocket.

First, I’m going to run it through Xentry somewhere to see if it’s just a sensor or something simpler than I’m expecting. I’ll keep you all updated over the coming days and weeks.

Thanks again!

PS. Arrie, it's a left-handed drive. German cars in Japan are mostly left-handed. It's fairly easy to drive right-hand drive cars in Canada, a bit of a headache at the start, but with a bit of dedication and searching, anyone can find an insurance company that will take you.

 

If you didn't find a solution yet I can help you find S350 airmatic struts front & rear.

Under no circumstances should you regress to springs, (?????!?!?!?!?!?!?)

Let me know if you need help finding the struts, I understand German & I can help you find a good set on eBay.de and guide you through the customs import to Canada, it's not as horrible as it sounds.