strider-g3

Hi all, I own a 2002 S55 AMG with 105,000 KM (N/A motor) and recently had the fuel lines repaired by a shop that also replaced my brakes. The car has been parked for many months prior due to leaking fuel lines. When I bought it earlier this year, I didn't have any ABC issues.
The only thing to note is that I removed the battery for many months during summer and when I did turn the car back on, it was just to tow it on a flatbed twice from one shop to another.
When I left the car sitting for a few months, the suspension at the front was slammed to the ground. But when I turned on the car and pressed the ride height button, the car jumps up and suspension is back to level.

When I finally got the car back with fuel lines fixed, I drove maybe 20-30KM and now I have ABC message in RED every time I start the car and I can hear / feel a low growl / humming inside the car.
The noise pulses and comes and goes. I have only driven maybe 3-4KM with this issue and am not driving the car anymore. Most people say to check the ABC fluid and run the car in Rodeo mode and do a drain / fill.
Can anyone help guide me to a shop in Toronto that would do this and not charge a lot? Just spent $1000 on repairs this week and the car is already needing more.
I'm told 10L is the minimum amount of fluid to have? The suspension does not sink on any corner even after the car is parked a few days. But after about 10-14 days, the front end is much lower than rear.
I have not touched the suspension button or ABC button to try anything. I'm thinking of opening the ABC fluid reservoir to check the fluid level but some people say even that's dangerous due to contamination.

Looking for some help / guidance on what to do. Car drove fine going over bumps and all during the 3-4KM i drove.
I have seen various YouTube DIYs where people are using a pump to take out the old fluid into a bucket and put in new fluid and change filter.
Should I do this? Or is the only way to do this using Rodeo mode so the fluid is totally cleared out?
Or is the fluid not the issue? From googling, I can tell the ABC system is very complex and has a lot of parts that can and will fail..
I just want to minimize damages to my wallet.. Should I just convert to a coilover setup? Has anyone done this? If so, from where and at what cost?

Thanks for your help in advance!

tusabes

Since you haven’t even checked fluid level you definitely need to ASAP . Don’t drive it till you check fluid level

You’ll be fine it’s easy to check level it has a dipstick just wipe all the dust clean around the reservoir first

there are two dipsticks the large reservoir is abc and the small is power steering. check both of them . They both use pentosin chf11s fluid which many large auto parts stores sell

a car that stays up for 10-14 days before sinking is fine , you need to drive these Cars regularly , at least once a week otherwise the battery dies too

strider-g3

Thank you for your response. I checked the fluid levels for both when car is cold. The power steering was VERY low. Just a drop on the edge of the stick.
I topped it up using CHF11S and not sure what to do now? Should I turn on the car and let it run or drive it at all?
I did notice the suspension is more bouncy when I drove last time with the humming noise from the pump and ABC light on.

tusabes

Fill both abc and ps reservoir to proper level then drive it to check for bounce and warning messages

strider-g3

The ABC reservoir is almost at the right level WHEN COLD. Should I still add fluid?

tusabes

That’s still low, I t’s below the bottom line . Fill it to top line

Fried Chicken

Sssshhhhhh, Calm down.

Don't let yourself get psyched out by the ABC system. It's just hydraulics (an ancient technology) with a pump in the front, and electronically controlled valves coupled to ride-height sensors to keep the car nice and level.

Your level is a little bit low, but it shouldn't affect the system (it drains from the bottom of the reservoir). Regardless, correct it. The entire system holds like 4 liters of fluid. Don't worry about doing a flush. Find a shop (with a proper mercedes computer) that can pull the codes for you to explain the red ABC light, and post what the ABC codes you're getting are. THERE IS NO POINT IN GUESSING when trying to diagnose this. You'll go insane.

It sounds to me like you might have some air in the system, and maybe need to replace the pulsation damper. A rodeo would rectify this (while doing a rodeo, doing a flush isn't a *bad* idea, but I think flushes are overrated). The system holds like 4-5 liters and a flush takes like 10. Again, I think flushes are overrated.

strider-g3

I've taken some deep breaths after reading your response. I will get the car diagnosed but wondering if I should drive it to the shop or not? I have towed it twice this month already due to the fuel leak which is thankfully fixed..
I have topped up the fluid for both ABC and Power steering but I haven't turned the car on. I can tell the suspension is starting to sag on the front left. The front right is also sitting a little lower.
Car has now been sitting for 3+ days since last being driven / turned on.
I was quoted about 700-900$ (depending on what type of fluid i choose) for the rodeo test / pump out and refill method by a shop that is 45 mins away... I would have to tow it there. The fluid is expensive and they recommend buying 14L of it.. Sounds like too much if the system only holds 4/5L?
The fluid color right now is not at all green, its almost brown looking...

tusabes

Wait a second , you filled it up but haven’t driven it to see how it reacts now with full fluid ? You have to drive it !! It’s not going to magically raise itself just sitting there . Just turning the car on isn’t enough , my car does not raise until I drive it

you actually need to drive it now that it is full . Then report back .

strider-g3

So I drove it around the block and took the car to fill up gas. Not much driving but I let it run for about 20 mins or so and saw that the fluid inside the ABC reservoir went down by a lot once the car was running. I topped it up and now the level is almost in the center on the side that says "AN". I have now poured the full 1 liter bottle of CHF11S.
The car has leveled out front and back, no warnings on the dash so far after about 30 mins of letting the car run and driving it around the block. The ride isn't bouncy either.

The only odd thing I noticed is a humming that seems to go away after 2K RPM. It happens whether I'm in gear or just in Neutral. Not sure what it is?
The pulsing sound / sensation I was feeling before (when fluids were low) is no longer there. But now I have a constant hum from the engine / transmission when driving or revving below 2,000 RPM. Any idea what this could be? I pray the ABC pump is okay...

The sound / sensation I was feeling before (when fluids were low) is no longer there. But now I have a constant hum from the engine / transmission when driving below 2,000 RPM.
Should I keep driving it with the hum?
Any idea what this could be? I will continue to monitor the suspension height and the level.

PS, I overfilled the power steering fluid and its WAY past the MAX marker. The whole stick is drenched in fluid. I think some even overflowed out once I let the car run. Should I take some out?

Thank you for your replies and guidance!!!



I have filled it till here with the motor running.. Hope that is the correct level it should be at

The color of the fluid in the system...

strider-g3

So far I have driven the vehicle a few KM on local roads and haven't noticed any red ABC lights or bouncy suspension etc. The fluid looks to be holding at the correct level when car is on or off. Today I pressed he suspension raise button and nothing happened. I pressed it and waited, then pressed again and waited. No change in height. No noise or message indicating it was even trying to adjust so I'm not going to try again until system is diagnosed.



Not sure if anyone had a chance to see the video I posted but could it be that I have that humming from the power steering pump since fluid was super low and is now over filled? The sound is a humming and is directly related to the RPMs when driving slow or revving under 2K. After that, I can't hear it and it goes away. Wondering if this is a power steering issue and what I should I do about it because it wasn't there before

strider-g3

Update: after doing some research and googling - I found the humming / pulsing noise is going to be either of the following: I will have them replaced and report back. Thanks all again.
Accumulator or Pulsation Damper

tusabes

it’s not the accumulators , if the accumulator failed your car would be bouncy and the abc reservoir would be lower than it was and you would get red warning errors on dash when going over bumps