Hi fellow GL owners. I'm sure you all have had some form of issue with the air suspension on these. Mine has been a roller-coaster of emotions.
Had issues Front Right Strut leaking and sagging, and compressor not operating as efficiently.
Strut replaced and valve block replaced. This fixed the leaking bag and removed that code. Then I had a code that the air compressor was not working efficiently. Replaced it with a new one and that code is gone.
After that I now get a different code, but only when attempting to raise the vehicle with the button.
I press the button and it starts to raise the vehicle, but stops at a point and gives a "Malfunction" message. When scanning with XENTRY, the only issue that comes is "Suspension Strut is Implausible" and what i notice is the other front strut did not replace is at ~20 Bar pressure while the others are at normal pressures.

This one strut (FL) seems to always be at a higher pressure. When I manually make the car go back to automatic height, it will move to the right height, but that one strut is always at a higher pressure. This is normally not an issue as it normally keeps the car leveled at normal mode and can raise and lower all bit. Only Malfunction comes when you try and raise it.

Can anyone help me diagnose this before i go an buy another new strut? Why is the pressure so much higher in that strut when its not leaking and can raise and lower manually with XENTRY. But its abnormal pressure in it.

Issue I get when Raising the vehicle or sometimes when Towing.

 

Level sensor overtravelled

 

Level sensor overtravelled?
But when I manually set them all to -30mm they all read equal and about accurate. And the sensor voltage and distance moves according when I push down on the car and make the suspension work while watching the data.

 

That could be why if you manually set a sensor to -30 and it’s actually not that you get implausible inputs.

Visually check each sensor for its orientation to ensure that the link hasn’t over traveled and is operating in the opposite range. Some of these also have a tendency to go soft and bend. Make sure that’s not the case.

I would not trust Xentry implicitly when troubleshooting automatic, it is more a pointer as to where you should get your ears and eyes into.

Also, you should have replaced both front bags on the first one failed as the system is particularly adept at finding the weakest spot in the chain.

Your compressor failed because you had other leaks in the system, and I would have retained the original valve body if I were you because the aftermarket ones are mostly junk.

So I would recommend putting back the original valve body; changing the left front bag and, you had mentioned that you did replace the compressor already so that’s fine.

once you’ve checked that all level sensors are visually orientated in their normal range of operation, do an automatic calibration, log out of the system and back in and rock the vehicle back back-and-forth, looking for similar voltage fluctuations. If one of these is truly out of band, it’ll be evident here.

so, to recap - check all level sensors are straight and not over travelled

Also, check / change that front left bag because it likely has a leak in it which requires constant refilling, thereby the higher pressure when reading it out. Bags have a tendency to leak in only certain positions because of how the vehicle is parked, and how the rubber folds lineup with existing cracks in the material.

 

You are getting some good advice.
1. I have rebuilt 3 air suspension 164 and have learned a lot each time. I will only use Bilstein’s on the front end and will not replace bags only with products like Armott.
2. Will only use German parts for compressors and valve blocks.
3. If you are having a hard time finding an air leak and one definitely exist don’t forget to spray the black epoxy on the bottom of the valve block especially on the china made blocks.
4. IMO the correct way to change a valve block is to slide the airlines into the new block engaging the brass ferrels without unscrewing all the fittings on the new block.
5. When I talked to a few MB shops searching for info on my suspension issues all shops said the number 1 failure are the arms freezing up for level sensors … Max gave you a lot of instructions to look at your arms and sensors … you should be able to get the voltage readouts on the Star System .
….. Good luck and don’t be afraid to reach out thru the message system .

 

Thank you so much for your input. Im fairly new to the Airmatic system.
I checked the level sensor on each wheel, and did notice like you said that the arms (level sensor linkage) was rusted barely moved causing the rubber arm to bend sometimes. I removed all of them, cleaned them out really good and greased them all. They now spin freely and move like butter.

While doing that I checked to see if the level sensors themselves, and they all move freely and have no play, voltage reading on all them work and move as the sensor moves.

After doing all that I noticed that the pressure in the bags is different.

When using DAS to "Set vehicle to calibrated level Automatically" it adjusts the suspension so they are all ~ -30mm and they read all accurate (using a measuring tool to measure from fender to wheelcap) only issue i see is that one of my front struts seems to fill with more pressure always. Even though its at the same height. For instance, at -30mm FL would read ~8BAR , and FR ~10-14BAR.
There are no leaks anywhere, if I leave the car for days standing in the garage or outside at -20°c the car does not sag. This is normally not an issue, but when I press the "Raise car" button. It starts to raise the vehicle and at the end it gives a malfucntion (not sure if it finishes or not but it definitely lifts everywhere) and checking DAS it shows that a strut reached 19.2BAR, which is where I assume the malfunction came from.

This is so weird, because last week it was the opposite where the FL was at around 14BAR and FR was at 8BAR. They basically swapped pressure. But if I don't raise the vehicle I rarely get the malfucntion, sometimes when towing or on random startups rarely.

But I'm the type of person who wants everything to work, and really want the raise feature to work, especially with the snow we get here.

Any ideas? Again thanks for all the input so far!

 

I think your new valve body is leaking into the front right strut. Do you still have the one you took out?

 

Yes I do, but explain this then. Why is it that last week it was the opposite then that the Front Left was usually overpressured and then pressing "raise" that strut would be ~19bar and give a malfunction. I have the old one I can try and swap. I replaced it because I thought it was leaking but it turned out to be a front bag.

But this valve body is new but not OEM. But when using DAS and manually actuating it seems work as it should. However there was one test that when running it seems off to me.

I will record that video and upload it to see in a bit.

 

Here is the video of the test I was talking about, this was last week when the overdressed was on the Front Left strut. This was before fixing all the seized height sensor linkages.


Tomorrow I will run the test again and upload an updated video.

 

Run the Xentry leak checks on this new valve before you swap back the old one, but my guess is that it’s suspect. There’s been a rash of really bad aftermarket once. The first thing you should always change is the bag the valve bodies rarely ever faulty, unless you’ve got moisture in the system.