Hi: I am looking at an '11 SL550 with about 45k miles. I used to have SL's but never had them beyond about 30k mikes but the fever has struck again. My concern is the maintenance, specifically the ABC system. Most of what I read on the forums is costly repairs to 2003/2004/2005 models. Did the ABC system get improved in later years or are those owners just nto having problems or not on the forums. Obviously, I know that if I am buying a complex vehicle and getting in for $40k or so, it will need some maintenance but I hesitate if I am going to have to spend $8-10k in next year or so. I would be better off to just not buy or buy something newer and pay more for it. For me, this car would only be a weekend/occasional driver to enjoy on nice days. On a side note, what about the other components? Again, not so concerned with costly oil changes, brake pads, even rotors or disks.
What are your opinions on the likelihood of ABC problems in NEAR future and costs to maintain an '11 w/45k miles that appears to have been taken care of? thanks for your input in advance.

 

I have an 11 SL550 (I purchased as a CPO that was still under the original factory warranty). The one year CPO warranty runs out in June I believe. Anyway, someone else will offer more details but I believe the ABC underwent some revision around MY2007. Among the revisions was a more restrictive filter. I have posted before about my opinion of the reports of ABC issues. Not scientific or absolute by any means, only my opinion based on reading and my experience. The ABC is a high-pressure hydraulic system with electronic sensors, servos, etc. The hydraulic portion is not new technology. Hydraulic systems have been used reliably on aircraft, construction equipment, etc. for decades. One difference is the end-user. Aircraft and construction equipment are maintained, or expected to be serviced, break, repaired, maintained, etc. Aircraft have a more rigorous maintenance standard. Anyway, if one looks at the ABC as requiring some maintenance, which MB seems to do its best to avoid, I believe the results are different. ABC has a pump; pumps wear, they break, etc. But mostly they last a long time, whatever that is. Struts wear, seals get old, fluid gets hot and degrades, rubber hoses age, etc. Within a month of getting this car (with about 21k miles) I flushed the ABC system and replaced the filter. I had my indy mechanic do it because I also wanted him to look over the car. The fluid was not the worst either of us had seen but it was not the bright translucent green is it is when fresh. Keeping the fluid fresh, keeping the micro particles that can wear parts, seals, etc. over time, just look at it as preventative maintenance. I plan to flush every couple of years. One of the hardest things on these hydraulic systems is lack of use...I am guilty of that. Keeping all the parts moving, adjusting ride height while sitting at the stop light, some long spirited trips to be sure everything gets 'exercised'...all good for it. Liklihood of a problem in the NEAR future? It seems unlikely assuming the car has been treated and driven normally, but it is sort of like asking when is my light bulb in the kitchen going to go out, need replacing. There is a lot of noise about the ABC system. I believe the vast majority of them function without major repairs despite not having the fluid flushed regularly. It can be expensive depending on what breaks and where you are when it happens. In the end it goes with the franchise. I had a 2004 SL and went through the exercise of well, is the ABC really worth the risk? I finally got over it. I really liked the car and while the idea of shelling out several thousand dollars to essentially replace the ABC system was not appealing, I could do it without jeopardizing my next meal :-) A complete replacement seems unlikely but some parts here and there? Possibly. It is an active suspension; there are different ways of achieving active suspension but it is the way of many high-end cars. Good luck on your journey...Mark

 

Mark:
Thanks for your input. everything you said makes sense about hydraulics. I am in the construction equipment business and preventive maintenance is the key here too as hydraulics control most of the functions. Of all the cars in the market, the SL has long been my favorite(close second being Porsche 911s I have had but alot rougher and louder) and I want one but now bad enough to pay $100k+ for the current new style. My only reluctance is getting comfortable with the ABC issues. If I had to spend a few thousand on it, I could and it would not wreck me, but I just like knowing what the exposure is as much as that is possible. My original plan was to get an '08 but miles were too high on those but the '11 is newer and has lower miles so I think I'm willing to put up another $13k or so for the '011. Now, if I want to add another $20k to that, I know of a '15 with 5k miles I could have....It seems, of all those, the '11 is the best option.

 

Understand and agree completely...I bought my first one (04) then began to learn, ask questions which is why I wrote that I eventually got over the concerns. Of course I opted to get a newer one AND really like the facelift of the 09, 11 and 12 MYs. For my tastes I was not interested in the redesigned models beginning with MY13. Just don't like what they did with the exterior lines, nose. Lucky, too as obviously would have cost more money. I love this '11. Did not run across a 2012 low mileage cpo when I was looking. Other than the fading rear outside pillar covers (seems common) which were replaced under warranty, only issue I have had was with the display. The LEDs had some uneven lighting. Very subtle. I actually only noticed it on my long drive home from the dealer in Virginia. Thought about it and said ah hell, it's under factory warranty...keep driving to Atlanta. It took some effort but I finally got the shop foreman to see what I was talking about and he agreed. Then they installed a scratched display so they had to replace that. Otherwise no issues, yet. There are lots of places for something to go wrong but hey, it's a complex vehicle, which is part of the attraction I suppose. It has an interesting braking system. You seem like the kind of person that might be interested in learning about that as well, unless you have already covered that. Mark

 

Yes I am interested in learning about the brake system. I'm sure it is complex too...which usually mean expensive to maintain and repair. Since I am a 'close is good enough' person, I am not a DIYer, so I have to pay big money to get this stuff done, but I think I will let an indy mechanic handle whatever he can. I recently started using one for a family member's BMW and it was more convenient, quicker, and certainly no more costly than the dealer.

 

Start with this. https://en.wikipedia.org/wiki/Sensotronic_Brake_Control

Gives an overview. There is a youtube video floating around that explains its operation also. Some refer to it as a 'brake by wire' system, meaning it is all computer/servo controlled. The pressure you feel from pushing the pedal is put there to give you the sensation you expect after driving other cars with 'normal' braking systems. Also there is a useful life to the main part of the brake system. I forget, switches, brushes, something like that. I believe I read once that after 300,000 pumps it forces you to replace. Don't quote me on any of that but there is a shred of truth in there somewhere. Some of the experts may explain more fully. I am like you...I have limits to DIY things, often because of time and equipment. I have an indy nearby that is very busy and been in business a long time. Maybe that means he is good. Mark

 

Well that just adds more complications....Once again, I suppose if you are into cars, this is what you have to live with. If you want transportation with a comfortable seat and good stereo, one probably needs to stick with a simpler vehicle. All the systems sure make BMW's seem like 'easy to maintain' vehicles..