I appreciate very much all you replies. J
The car in question is an 1988 S124 200TD.
It feels strange being the accumulators because I change them 100K ago. Before I change them the ride was very bouncing, if you had a ball in the trunk it will hit the roof.
Now doesn’t bounce, but feels hard, you can feel every bump on the road, even a small imperfection. It´s banging quite loudly over bumps!
I´m gone to check the accumulators. J

If you're getting bumping or banging noises you might also check the sway bar links. They are S shaped things with ball joints on the ends that attach to the end of the sway bar in the rear. The ball joints should have boots and they joint should be stiff. If it's loose or wobble it's time for new ones.

Ok! Thank You!
I Will check that.

I´ve check the rear axle, and found that a suspension arm is kaput.
Thank You!

please take pictures of what you found and post them here!
WE LOVE PICTURES

Ok so I have an 82 300TD with the SLS and a bad diesel engine.

I bought a sedan engine. I was told that the "power" for the SLS pump comes from the head of the engine.

So how do I fix this problem so I can put the sedan motor in my wagon and still have a working SLS?

Swap the cylinder heads.

W124 SLS Issues
 

New member to forum, was really happy to see such a complete write up on W123 SLS. While the SLS is functionally similar in W124, are the leveling valves (and repair) the same? My '87 300TD SLS jacked the rear end up as for a heavy load, even though there was no load, after only 432K miles. I read your (Biodiesel300TD) troubleshooting guide, but didn't find a "rear end jacked up and rides like shocks are bad" write up. D you have a guess as to what my problem might be? Do you have a kit for W124 valve (if that's the problem)? Do you offer rebuild service? Thanks for your help, David E

Unfortunately the 124 valves are not rebuildable. They aren't designed to come apart like the 123 valves are. You can get to some of the o-rings but not all of them. If the rear is riding high all the time I'd look at the connecting rod between the valve lever arm and the sway bar. It may have become disconnected and so the lever arm dropped down, making the valve think the rear is sitting low so it's compensating. If this is the case your car is sitting at its max height and probably riding bad because of it.

Hello everybody,

I am new to this forum and found the "write-up" on this thread amazing. Thank you for sharing this information with the rest of us.

I have a situation that has begun to concern me. The self-leveling suspension on my 1991 Euro 190E 2.5 16V works perfectly and does not go down at all (even when leaving the car parked for 3 weeks) or leak. However, with the engine running this valve (PN: 123 328 0531) produces a "thump" noise every 3-10 seconds (frequency varies). I would like to know if anybody has experienced this condition/situation and if this is any sign of "imminent failure" of this part. Any words of wisdom would be appreciated.

Best regards,
Slfan1

Re: jacked up rear on W124 w/ SLS. You were exactly right about the connecting arm coming loose. I feel lazy not looking underneath before posting, but I was still full of turkey. The ball and swivel attachment at the valve has corroded and I won't be able to reattach, but the dealer ordered a new connecting rod for only $41. I don't think my zip tie is a long term solution. Such is the cost of driving a luxury vehicle. Thanks again for your help, David E

At least you knew what to look for when you climbed underneath.:D Glad I could help, and it was an easy fix! Happy motoring.

That part is the SLS valve. It's responsible for maintaining the level of the rear. I've never heard of the SLS valve making a thumping noise. Are you checking this while under the car with the engine running? If not I'd do that so verify that is it that valve itself and not something else. Does it do it while while sitting or when lifting or raising? If it is the valve I'd suspect that it is a sign that it's failing. Make sure the system is full of fluid. Unfortunately there isn't much you can go with those valves. A new one or a good used one is the only option if it is failing.

BioDiesel300TD,

Thank you for your answer. I had the car raised on a lift with the engine running and can confirm that the thumping noise is coming from the SLS valve. Any advise where I should procure this valve?

Thank you,
Slfan1