W220 Option code confusion - thoughts please?

[markben]

Greetings to all here. Apologies for this long post but you might understand why...

I haven't bored the daylights out of you recently about my long running 'mystery' Hard Damping 'HD' problem (always in Comfort mode) but someone here might be able to help?

The background & symptoms in brief:
long standing HD / too stiff / very harsh ADS damping invariably, but with rare, brief 'softening' ('Magic Carpet' - as it should be) in sudden colder weather. Various Indies (no names mentioned) have replaced all 4 Struts, ECU, Compressor, sensors etc etc with brand new OE at massive cost £££. But.. never any fault codes on SDS & the usual verdict is 'it rides ok'. Mmmm...

A recent new Indie (#6) has driven 'The Limo' (my otherwise immaculate & well maintained 2004 S320L cdi) over rough roads and agrees about the HD problem compared with similar W220s he knows. That's a good start and reassures me that I'm not 'imagining' the HD problem - as one indie politely suggested.

The latest Twist:
New indie reports that the car has factory fitted 'sports suspension' according to option code 674 on his database (correct VIN provided / screen shots of his readout sent to confirm). Therefore, he is certain / the data explains why the car rides 'as it should', i.e. stiffer than standard spec. and with no faults on SDS. Mmmm.. ?

BUT..(!) on my / the car's original data sheet, option code 674 refers only to '17" 5 twin-spoke alloy wheels + wide tyres'. NO mention of 'sports suspension' for code 674 nor anywhere else on the data sheet. Also, NO mention of code 647 'sports suspension' as a factory option anywhere else - including in the original sales brochure, on W220 ee. Wikipeadia etc. That's the Puzzle.

And.. W220s already have Airmatic / ADS with switchable Comfort & Sport 1 / 2 modes as standard equipment. So, by my logic, any references to, or claims about factory fitted 'sports suspension' are either due confused terminology on the Mercedes database / EPC or for some other reason? Mmmm.. again.

Through this HD saga (& despite the latest indie's verdict), my best guess is still that there's a 'hidden' fault in the ADS circuitry which is causing the HD problem. You tell me?

If you're still following this, you deserve a medal. But seriously, all thoughts & comments will be much appreciated.

Many thanks for following.

Mark B.
'The best or nothing'

 

[markben]

Update:

A pal on another Mercedes forum has solved the coding mystery.

My new indie was searching Xentry where the 674 code description (sports suspension) is not correct. EPC code desc 674 (wheels etc) IS correct.

So it's back to him to set the record straight about his (incorrect) Dx of the HD problem AND.. ask him to go back to square one with other investigations (looking for that hidden fault in the circuitry etc). Hey ho...

Many thanks all.

 

[ALFAitalia]

Wow you must have spent a small fortune (close to its market value I would suspect) to get.....well....not very far. Your patience exceeds mine sir, that's for sure. Parts darts, when the parts are expensive S Class Parts, is not a game I'd want play!

 

[markben]

Wow you must have spent a small fortune (close to its market value I would suspect) to get.....well....not very far. Your patience exceeds mine sir, that's for sure. Parts darts, when the parts are expensive S Class Parts, is not a game I'd want play!

Thanks. Well yes ££.. but over 10 years & 50k miles in my ownership the now nearly 22-year-old 'Limo' been pretty reliable all considered, incredibly economical on fuel for its weight & power (that robust OM648 cdi engine), always a pleasure to own & drive, 'timelessly elegant' and much admired.

It's cost me approx £2k on average per year to maintain (exc. tax, insurance & fuel), so I see the occasional big expenses £ (new air struts etc) more as an investment than an expense to keep it in tip-top condition when a much newer 'S' (say 8 years old @ £25k+?) might be as / more costly to own and less 'special'.

Also, 'The Limo' has an intriguing back story & huge personal value due to my connections with its previous owner (RIP) in my past life as a Mercedes sales exec 30 years ago. That's why I bought it 10 years ago and intend to keep & treasure it, regardless .

 

[surfinsilver]

Dear Mark,

I have been following your threads with great interest even before I became an S owner. (Currently in a W221 S350 CDI)

I too am suffering from the same mystery hard damping issue but with a crazy twist... i've experienced it now on 6 different cars.

Now for anyone reading this, yes I know that's impossible, I've already been told its in my head. I am aware I might have a mental problem!

4 of the cars were all from the same manufacturer, same model but different engines.

The fifth was a D4 Audi A8 and now the W221 S.

I have driven many other examples of all the above and all rode far better (read: softer, more comfortably and less jittery) than my own at the times I owned them and did the comparisons.

Another twist in my situation is the steering and engine performance were also effected in the above cars. (Steering heavier and engines feeling laggy and lethargic)

I am able to prove that I am not alone in this as there are people over in a large far Eastern land who have the exact same problems (ride, steering, performance) on Land Rovers and S classes. (I haven't been able to find someone with the exact symptoms on a D4 A8)

Like yourself Mark some of them have been at it for over 10 years with no luck in solving the problem.

I am sorry that I cannot offer any suggestions on a fix, my own journey with this frustrating, depressing set of problems has so far lasted 8 years and cost in excess of £100,000 in trying to have a car that drives, rides and steers as it should.

You are not alone.

 

[surfinsilver]

I should also point out that all the above cars to which I refer were extensively test driven prior to purchase to satisfy myself I was happy with them.

All but 1 drove correctly for a couple of days before the symptoms set in never to go away.

The 1 exception car drove perfectly well for a good couple of months before hitting a rough patch of cobbled road at which point it did a 'Jekyl and Hyde' and developed the same 3 problems as all the others.

 

[markben]

I should also point out that all the above cars to which I refer were extensively test driven prior to purchase to satisfy myself I was happy with them.

All but 1 drove correctly for a couple of days before the symptoms set in never to go away.

The 1 exception car drove perfectly well for a good couple of months before hitting a rough patch of cobbled road at which point it did a 'Jekyl and Hyde' and developed the same 3 problems as all the others.

Greetings surfinsilver

Well, where to start?! My best guess at an answer is that these types of 'mystery' problems can be for a variety of reasons including any or all of:

Erroneous electrical faults which Dx systems can't detect (quite common on older cars, especially the electronically complex Mercedes S Class). I remember owing a electronically controlled hydro-pneumatic suspension Citroen XM many years ago which was schizophrenic in terms of ride quality. Usually, sublimely smooth & soft. But sometimes suddenely rock hard like a go-kart. Even my Citroen main dealer couldn't get to the root cause of the problem.

Even on 'like-for-like' / supposedly identical cars, variable factors such as differences in tyres (make & quality, rating, wear, pressures etc), wear +/- in suspension components (e.g. bushings etc) & mileage can make a noticeable difference.

Ditto with engine power & steering 'feel', possibly due to slight variations in manufacturers' spec. depending on engine type etc?

Of course, subjectivity can come into the 'it feels right or not' equation too, and in parallel with the above.

Also: 'selective memory bias & perception' can distort objective reality. For example: from my memories as a MB sales exec 30 years ago, I swear that the then new Mercedes W140 (on coil springs) rode more softly than my much newer W220 with Airmatic & ADS. But I can't verify this with a back-to-back drive for various reasons including that both models are now quite old.

I think the bottom line on resolving these types of perceptual dilemma is ultimately to decide whether a car is 'tolerable' in terms of the driving experience, or not - within reasonable expectations? That's assuming other variables have been ruled out.

Searching for 'perfection' in any car can be a long & frustrating process, as I know on my otherwise immaculate (but too harsh riding) W220. That said: after 10 years & 50k miles, I've sort of got-used-to, and can tolerate it from day to day until or unless I can find the ultimate solution ('Magic Carpet ride' etc). That's 'work in progress' as always.

Hope this helps & best regards

Mark B.