The passenger rear of my 2003 SL500 with 46k miles sags if I don't start the car for 2+ weeks. Once I start the car up and raise it and lower it, it comes back to normal.

I am not driving the car at all during winter except just taking it for a couple of mile long spin.

Is that normal? I also gets "electrical system offline" and something to do with brake not fully operational errors but when I drive the car a bit the errors go away.

I also get "Coolant level" error and it goes away as well when the car warms up after being driven a bit.

I do not have the car on a trickle charger and is parked inside the garage.

I did have an ABC issue a few months ago and it turned out to be leaky line which was replaced and the fluid refilled and topped off.

I just wanted to check with you guys to see if this was normal.

Please advise.

Thanks,

Paul

 

Sounds like you may have a little leak-by at your rear valve block. Your rear valve block has valves which block fluid in the struts to maintain height when the car is off. There are O-rings that can leak and allow the effected corner to sag.

There are tutorials here on the forum on how to disassemble the valve blocks and replace the O-rings for a few dollars. I posted a DIY here in the forum when I rebuilt both my valve blocks as preventive maintenance. The dealer will tell you the valve blocks cannot be serviced and want to sell you a new one for a couple grand. If you don't do your own work see if you can't find an indy who will do it for you.

It may be possible that the strut itself is allowing the corner to sag but it seems more times than not it's the O-ring seals in the Valve Block failing.

 

I have since bought CTEK Multi 3300 trickle charger and have noticed that since the battery levels are staying at adequate levels, the suspension has not sagged as of now. I am closely monitoring it and will keep you all posted.

Would a dead/low battery cause the suspension to sag?

Thanks,

Paul

 

I had the same problem when I didn't drive the car for 2+ weeks. It was happening to me during the warranty period and the stealership replaced the whole front passenger shock assembly. If it is just the fluid leaking by the O-ring then the battery charge should have no effect. There shouldn't be any sensors monitoring the ride height when the car is off.
It's good you bought the trickle charger because I had to replace my battery from not driving it. I have a trickle charger on mine now too but the best thing to do is drive the car whenever possible.

 

I found a DTB (Dealer Technical Bulletin) which covers your exact condition, see condition 2 in attachment. You will be relieved to find that your car is acting normal per MB.

Keeping your Pentosin clean is paramount according to this post. vtvette has some excellent posts and advice on the ABC system.

Bob

 

SO if i am reading this bulliten correctly, if there are no error codes, and your car drops after being idle for a week or so-that is ok
and also there is a little more to a full abc fluid flush, than emptying the resorvoire . it should also be bled via the valves, and those ****,by design,accumulate debris, should be cleaned when the resorvoire is empty.
perhapse going in with a turkey baster to that tit may help remove debris, or it may even open a can of worms by kicking up more sediment.i have done vtvettes excellent method of fluid displacement, but did not know those areas at the bottom of the well were there.good bulletin mercy

 

Good read, should the system be cycled (warmed up) prior to the fluid change?

 

Thank you everyone as I don't think this has been discussed previously with all the other ABC issues that are a usual discussed on this board.

I am happy to further update you on this. With the car being plugged into the trickle charger, the ABC has not sagged. Also, as I mentioned earlier, there was a leaky hose in the car that had caused the ABC issue a few months ago. The hose was replaced and the fluid was flushed and filled. So I have fresh fluid in the car and had it checked a few weeks ago and it was completely full.

I will provide additional updates in the next few weeks. At this point, I have not driven the car for over two weeks and with the nasty weather here in Maryland, I do not anticipate driving it for another month or so.

Thanks again!

Paul

 

Paul, which hose did you find leaking?

 

So here's what happened any help would be appreciated. After driving the car all summer I found that the resonator sounds like it has marbles rolling around and probably it is the catalytic converter. So I park the car and find that the climate control has no lights and is dead. Prior to that the AC was blinking red lights and no compressor or AC. Now the control module is out...... I went to start the car and cannot turn the key and the cars is completely lowered. Trunk battery is fully charged and I did charge the starter battery. Key will not turn in ignition even when i changed the batteries in key fob. . Dash say Chip card not recognized for keyless go.. Im thinking it is a fuse but not sure where the fuse or which fuses it could be... Any help would be appreciated...

 

I'm popping in here late and it looks like you got a bunch of good answers on just about everything except maybe the coolant level warning.

If I am not mistaken, there is a sensor in the surge/overflow tank. It could be the level is just slightly low and the bit of expansion related to operating temp raises the level enough to turn it off. I have found that adding just a few ounces of coolant stops the coolant level warning from tripping. A coolant level warning on start up is not normal.

 

What are the stored DTC codes??

 

Not seeing any codes and am assuming since the issue goes away, it may not be storing codes? In other words, when the car warms up (its been a cold winter) the warning goes away.

Now in reference to the sagging issue, the passenger rear sagged a couple of days ago even after being juiced up through a trickle charger.

Then again, as per the Mercedes bulletin posted in this thread, it is normal for the car to sag if not being driven actively. I have not driven the car in about 3 weeks now.

Planning to drive it tomorrow as the temperatures are going to hit in the low 60s:-)

Thanks,

Paul

 

All,

Now I am puzzled. I drove the car on Saturday with the top down as we had a good 70 degree weather and parked it in the garage on Saturday evening. Its Wednesday today and the right rear has sagged some (not fully though).

I took the car to my indi-mechanic and he checked the fluid levels a couple of weeks ago and the levels were completely to the top.

The power steering levels were a bit low so he filled that reservoir up at the time.

Any ideas? I love the car but am concerned. It comes right up as it should so am just confused.

Thanks,

Paul

 

Your rear control block needs to be rebuilt or replaced.

 

Agreed.

 

When you start the engine and cycle the suspension height via the control switch or drive-off the suspension height will likely return to normal. Assuming it does, you may want to monitor this problem over the course of several days to see if it goes away. If it doesn't, you can choose to live with it.

If the condition persists and you wish to correct it, M-B states that you should filter the ABC fluid. This is explained in their DTB which was attached to post #5 above. If filtering brings no joy, then to eliminate the sag the valve block would need to be replaced with a new or rebuilt unit.

Filtering ABC fluid takes 30 minutes and requires a Star Diagnosis PC. You can purchase a Chinese clone for around $300.

 

Thanks I cycled the suspension and it came right back up. I am going to start driving the car more since the weather has gotten better and if I see it sag then that is certainly an indication that i would need to replace the valve block.

I will keep you all posted.

Thanks,

Paul

 

The ABC valve block has to be rebuilt. There are 2. One in front and one in rear. The O rings can be changed, but not necessary. The main problem is that there are 2 small springs in the valves that need to be extended. After years of use, they "dance" inside the valve. The ends of the springs become worn and they are not long enough to put enough pressure on the valves to close them. To rebuild a valve block should take approx. 4 hours start to finish. When looking at the valve block, there will be two valves that are the regulators. They control the height while driving. The other 2, which are the ones that have a tapered shape are the ones with the 2 stainless steel springs. If you look closely at them you will see that the ends of the springs look like they have been filed down. Simply stretch them out approx. 3/36" of an inch. These valves are shut when the car is parked and keep the fluid from reentering the reservoir. When they become too short to close completely, the car sags slowly after it is parked. In some cases, the ABC warning lights will not come on if you leave the ABC down while driving (both lights on the console off), but the car will raise when you put it in gear and will sag when it is parked. If after repairing the 2 small springs and the light comes on after driving with car raised, the other valve block's springs are wearing and need to be stretched. Replacing the fluid and flushing is recommended, but will not fix an ABC error. It is these 2 small springs that are your problem.

 

Great Post,
Are these springs available as a new direct replacement? I would think , over time, the spring fatigue would resurface quickly on a "stretched" spring.

 

MB doesn't sell just the springs and there is no way to get the exact specs to replace them that I know of. By looking closely at the very ends of these springs, you can see that they have been worn down. I figure that it took about 9 years and 93k miles to wear them down and by stretching them, I could probably go another 50 k at least before having to change them completely. There doesn't seem to be a reason that they have to be exactly as they were when new. It is a simple open/close function when car is turned off. I hope this helps. You may want to measure them and photo them before placing the valve block back into car so you can get new ones if you need to next time. I hope this helps.

 

It appears to me that some folks have been rebuilding their valve blocks themselves with success, and that's really great.

Those statements are contradicted by Mercedes technical documentation, posts from professional M-B techs on the forums, and the experiences of owners including myself.

For two years my car would always sag at the right-front within hours of being parked. Two months a ago I performed a rodeo and a flush, and the problem has disappeared. The car has sat idle for as long as eight days.

 

I am also one of the VERY FORTUNATE FEW that have self flushed system,displacing as much fluid as possible, replacing filter, and adding a magnetic filter...and the car has stopped sagging on the front left corner. it was sagging after 3-5 days.again i am fortunate my issue was prob small debris

 

You're right. I would replace fluid and do rodeo or manually run the car up and down a dozen times first. But if this doesn't do it, and all leads to the valve block, look at the springs. As far as the left front sagging more than the left, that puzzled me. I started with that problem, changed fluid, filter, flushed and rodeoed. No change. Next, changed o rings, and it still kept bowing to the left. I purchased the Star CD for my SL500 R230 and studied the schematic. According to the schematic there should be no reason for it to lean to the left or right other than one of the valves is leaking. There is a split block in the line that feeds both front struts equally and only difference is the 2 separate valves on the block. I measured the self lowering of the car overnight and both left and right would go down, but much more noticeably on the left. I also noticed the rear settled a small amount as well. According to the CD's schematic, there are 2 valves in front and 2 in rear that close completely when car is turned off keeping the current amount of fluid in the struts. The only reason at this point could be those shut off valves not completely shutting off the fluid and allowing it to leak back into the accumulator due to the weight of the car. The other valves had nothing to do with restricting flow in and out of struts when car is off. So, I can see where dirt could accumulate in one or more of the shut off valves, possibly blocking the valves from closing all the way. When I first rebuilt my front block, there were metal shaving and other dirt caught in the block. A thorough cleaning did not solve my problem, but could have if my springs were not worn down which I overlooked at the time. Those metal shavings could have come from the springs or elsewhere. A regular flushing, cleaning, and filter change, as recommended could keep those springs from wearing down as well. I did not intend to say it is always the springs, but if it comes to replacing the blocks, look at the springs. It worked for me. My ABC works perfectly now.

 

Great Info !!
Thank You.