jll280305

Hello everyone! Brand new to the forum so be patient. I was curious if anyone knew of a vin decoder or any other fool proof way to pinpoint what suspension is under my rig without tearing into it since time is limited? I want to start ordering some parts but some of the sites like Arnott are asking questions about ADS, 4 Matic, Airmatic, AMG, etc....etc.. Just trying to do all the prep work I can so everything is here when time permits me to do the work. I am guessing it is probably standard suspension in the front with an air suspension assist in the rear by looking at my on-board controls......... Thanks in advance!

Lioninstreet

Just look on your dash center below the radio. If you see something that looks like a SUV and a shock absorber printed on the buttons you have four corner Airmatic, Otherwise you only have it in the rear.

kombifan

https://www.datamb.com/

Lioninstreet

That works too...

For decoding German VIN's Ive always used https://carinfo.kiev.ua/cars/vin/mercedes/vin_check since my vin remains private.

Lioninstreet

BTW the rears from Arnott are pn# A-2597. If your going with that brand and you buy them new on ebay from anyone but them, there is no unlimited warranty. You would only get one year.

Just an FYI

jll280305

Thanks for all the info gentleman!

AFS2019

Hello - I am new to this community and not necessarily the most mechanically inclined but have read quite a few threads and appreciate the expert level advice that flows through these threads. I am trying to get my head around the W251 (2006) airmatic system and all of its components. I have had the dealership replace parts here and there (a compressor, a front strut …) but the problems seem to keep surfacing. About 2 months ago, the airmatic system was making strange hissing noises from the engine compartment but the dealer recommended the replacement of all ABS modules and that seemed to do the trick since there was also a recurring ABS error message. 2 weeks ago the car started leaning on its left side (driver's side) but once I turn the car on it lifts to its normal (or above normal) height - more and more slowly as far as I can tell. It takes about 3 or 4 hours for the car to sag completely on its left side. I was hoping someone could provide me with a general overview of all of the parts that come into play on this airmatic system. As far as I can tell I have a pump, a compressor, 2 front air adjustable struts and 2 rear suspension bags … but I am probably missing something as I sometimes see a reference to a suspension bag in the front as well. I bought the car when I lived in San Jose, CA but then moved to the southwest of France and I have to believe I was the first R350 non-diesel within a 100 mile radius. I am uncertain the local dealership has much expertise on these systems since they asked MB headquarters what to do about the sag and have not heard back from them in 3 weeks. I learned my lesson the hard way when I had electrical issues about 5 years ago (all of the rain water was being directed to a fuse box in the driver's footwell) and it took about $5,000 of repairs for MB Europe finally to admit to a design defect and to repair it once and for all. I am attached to this car so this time I am going to try to understand what components are at play then find a local repair shop with a decent reputation then work with them to get this car back on the level. It looks great and other than the fact that I have to pay $165 to fill the tank with 80 liters (any ideas on improving MPG would also be welcome) this car has been a joy to drive around Europe. Thanks much for any advice or information.

Lioninstreet

Feel free to correct me if I'm wrong, but if memory serves me there is also a load proportioning valve that adjusts the suspension height based on how much load you are carrying. From what you explained your issue is a failing air strut or air bag (depending on if the sagging is in the front or the back). Is the front left the same side you replaced the air strut on already?

AFS2019

In fact, it is sagging heavily on both the front and rear left side (driver's side). I had replaced the front passenger strut so this may just be par for the course. The car has over 200K klicks. I believe that the airmatic configuration that I read about in the forum requires a specialized piece of MB equipment so once I replace the front left strut and the rear bag I am wondering if the local MB will have what is needed to reset the proper config. I am looking into the DVD that describes the full R350 service process so that I can have a real conversation with the mechanic that will need to do the job.

houseofdiesel

Every 8-10 years the air bags need replacement. Period. On top of that, if left to run constantly due to air leaks the air suspension compressor will need replacement, it was not designed to have a large duty cycle, only occasional use. Do not use Arnott front airbag until they release a second generation, I have replace my fronts twice and the upper clamp they use never seals and leaks...from brand new. Once you have replaced all the air bags other common problems are the valve block in the right front wheel well and the fittings leaking at each bag. The lines are not known to ever leak or be a problem. The simplest solution to find leaks, a spray bottle full of soapy water (some dish detergent added to water) soak everything and wait for the bubbles/foam to appear. It is usually very obvious when leaks are present using this method. Cheap too so soak it down really well. Another factor that can shorten the life of the airbags is keeping them clean, grit and dust, dirt, small rocks get caught in the folds of the bags and very abrasive. Put it in the raised position and clean them once a year, wipe down the entire bag at all four corners.
Other items to keep an eye on, the level sensors are prone to seizing up. very simple device that needs a bit of grease in the ball socket every couple years, they are located on the front upper control arm and rear lower control arms. Once you have your suspension sorted be sure to have the ride height set (calibrated or relearned) and wheel alignment after that. They tend to ride high in the rear after time.

AFS2019

Thanks much for the good advice. I just ordered Arnott's full front springs with airbag (AS 2394) since I had read a few good reviews. I did see that you could buy just the air bag but I was not sure if that was a reliable way to go. I am getting a quote from the dealer on the air suspension compressor and will compare with what's available on-line. I don't have an attached garage so the bubble and soap method is not an easy way for me to go but once I get a better of idea where these components are located I might be able to find a quiet spot to pull this off - youtube has great info on car repair processes. I have read that you should only change the front springs in pairs and never just one - while I can understand this for tires, seems hard to believe for shocks.