Air suspension

[crystalworks]

Yes, both front fenders would be sitting on the tires if left overnight. Today the suspension is still up at pretty much full height. ~27.25" from the bottom wheel flange to the bottom of the fender. That's how BMW wants you to measure it when checking ride height. Works out to 692.15mm. BMW specs 708mm with the factory 20" wheel/tire combo. I'm guessing mine is a little off due to the aftermarket wheels and over sized tires.

TIS Ride Height Specs

So, in my case, replacing the valve must have helped, if not solved the issue. I disassembled my original valve unit that controlled the front air bags and it looks like the gasket that seals the body of the solenoid is flattened. So maybe a small amount of air was leaking out from between that gasket. I tried finding rebuild parts (o-rings, gaskets, etc) for the valves (3 of them on that unit) but Wabco does not sell individual parts. Only the entire valve. So I'm going to measure the o-rings and replace them and then seal the unit with gasket maker to keep it as a backup if I ever have problems with the valve I just put in.

[EODguy]

Hey CW,

Give your local co-op or farm equipment store a try as they have amazing abilities in having o-rings on hand or even making custom hoses and gaskets without requiring a case of beer and an industrial size bottle of lube to pay for it...

Sent from my SM-A730F using Tapatalk

[Patriks7]

So I finally managed to get DIS up and running and got the following error from it. Not sure what exactly all of that means.

I also reset the zero (I believe that was the terminology), as I was noticing that even when functioning normally one of my sides was a bit lower than the other, the difference was maybe 0.5cm and now suddenly it’s about 2cm! I will be honest, I have no idea how I managed to find the zero function (anybody have instructions for DIS? ), so I would greatly appreciate if someone could help me out to set the heights to be the same on all sides.

[crystalworks]

The ehc2 module lives underneath the spare tire in the electronics compartment. They are known to fail from water intrusion into the area from clogged rear sunroof drains. They are very cheap to buy used if yours is having issues.

Sorry, can't help with DIS as the foxwell is my go to for most service functions and code reading.

[Clavurion]

Actually the price a new original EHC2 module is nowadays half of what it used to be.

https://www.bmwautoparts.net/en/sear...ry=37146773999

[Patriks7]

Damn, still quite expensive. I, however, have doubts as I have never had any water in that area of my car, I check it quite often even while cleaning. Any idea what the mentioned lines and plugs could be referring to? I can‘t seem to find any documentation for this.

Since I did the reset of the whole thing, I have been going out to my car to measure how it‘s changing. The rear haven‘t move a bit. The front ones are dropping at about 0.5cm every 3 hours, which I am convinced is quite a bit less than before I did the whole reset, then it was quite visible of how much the car was raised even if I was half an hour at the grocery store.

I am coming to the stage where I have absolutely no idea what‘s going on anymore unfortunately my mechanic is booked out for months, due to the lockdown, and I am definitely not taking it to a BMW dealership.

[Clavurion]

Those lines and plugs on DIS picture is simply the plug housing on EHC2 module (voltage, ground and K-bus)

These modules are quite prone to fail even without water or anything else causing direct damage. Some where even renewed during manufacturer warranty.

[crystalworks]

Originally Posted by Patriks7

Damn, still quite expensive.

Yes they are. I apologize, I was thinking of the rear axle computer, not the 2 axle one in our cars. Single axle (37141092396) computer is cheap to buy and located in the trunk area by the battery. The 2 axle computer (37146773999) is a pricey little guy and is located up front behind the dash. That new price is actually pretty attractive comparatively as Clavurion pointed out.

Have you sprayed soapy water at things? It's a cheap, relatively easy, way to to see if line connections or seals are leaking. If both of your fronts are dropping slowly, that valve I replaced is a good thing to look at. Hard to access due to its location, but worth a look. I doubt both your front bags have sprung leaks at the same rate, at the same time. Though these are BMW's... so you never know.

[Patriks7]

Originally Posted by crystalworks

Yes they are. I apologize, I was thinking of the rear axle computer, not the 2 axle one in our cars. Single axle (37141092396) computer is cheap to buy and located in the trunk area by the battery. The 2 axle computer (37146773999) is a pricey little guy and is located up front behind the dash. That new price is actually pretty attractive comparatively as Clavurion pointed out.

Have you sprayed soapy water at things? It's a cheap, relatively easy, way to to see if line connections or seals are leaking. If both of your fronts are dropping slowly, that valve I replaced is a good thing to look at. Hard to access due to its location, but worth a look. I doubt both your front bags have sprung leaks at the same rate, at the same time. Though these are BMW's... so you never know.

I haven’t yet, trying to find the time for it, but other things are popping up every day, since my car IS working I don’t set such a high priority to it. I did spray the whole front bags about two months ago when I was changing the connectors and didn’t find anything on them. They were both replaced for the Arnott’s about 4 years ago I believe, so I have doubts they would have managed to form leaks, but you never know.

I will definitely try to find time in the next days to get to that valve though with some soapy water (btw did you do this as well and find some leaks?). Also, since I have not had the suspension working properly for what seems like months now, I am not sure what the proper working function is anymore. Today after resetting the system I went to drive it around a bit, and I noticed that the compressor was on for what seemed like minutes after starting the car. I’m sure this was in part due to the recalibration, but it also did it when I tried the car a few hours later. Is this normal? I could have sworn that it didn’t run that much.

[Patriks7]

Just thought I’d share when I say it doesn’t drop all the way. This was after the whole night so it won’t go further. Last time I had a leak it was literally fallen on the wheel, couldn’t even get a piece of paper in there.