Hi guys,
I recently bought a 2000 540i touring in Japan Red (the thread is in the general E39 section), and I had a more touring-specific question. My touring sits ever so slightly crooked in the rear, appearing to tilt slightly to the right. I have the sport self-leveling suspension. There's no hissing after I turn off the car, nor does the car ever drop down completely like it would if the air spring was completely bad. No error messages either. It's just this slight tilt. Though honestly I've never seen or felt the self leveling suspension doing anything in this car, so how would I go about checking that first?
Thanks!
1995 525i 5-speed - Thread
Hm, I guess I'll have to have my girlfriend sit in the car when she comes home after work tonight and see if the rear evens out. Right now there's no change whether the car is running or not.
Because I'm always way too eager to take matters into my own hands, I went and did some troubleshooting just now. I removed the cover behind the seats and examined the air springs. I made sure to double check the part numbers, since a lot of people seem to get the sport and non-sport springs confused. Both part numbers checked out correctly, being 37121095081 and 37121095082 which are the proper springs for the sport suspension. I did notice something interesting though, the side of the car that sits higher had a remanufactured spring with a blue "re" sticker right near the part number on the top of the spring, whereas the sagging side does not have that. Maybe the newer air spring is a little better at staying up than the old one?
1995 525i 5-speed - Thread
Wait, does it sag all the time on the one side or just after the car sits? If it's all the time, i'd hook it up to INPA or ISTA/D and do the rear ride height calibration/adjustment. You can adjust the height of left and right individually in the ride height adjustment test plan...
Alvin Caragay
Mpire Automotive (https://www.facebook.com/MpireAutomotive/)
'96 AC Schnitzer S3 Sport CLS Replica (https://www.facebook.com/ACSS3SportCLSR)
'02 E39 540iAT
1995 525i 5-speed - Thread
I reset SLS several times when adjusting my ride height in the rear. When you reset and then measure the cars ride height, the Driver's side was always higher. I think its OK, but perhaps some of the more tenured folks will pipe up soon.
99 540iT - Merlot Truckster (TCG done 134k, might sell...)
00 528i/5 - Grüen Arrow (sold)
93 740i - Grün Hornet (sold)
00 740iL (R.I.P.)
Right on. I'm installing INPA on my girlfriend's old Windows laptop, and I already have all the necessary cables from a year ago. I can't believe I've gone this long without INPA, but I guess I just didn't want to deal with the hassle of setting it all up on Windows (I literally have not used Windows since like 2008, I've been 100% Mac since then).
Oh, and one thing I forgot to mention— I went and disconnected the air line on the right air spring and then once all the air drained out it the rear end sat quite low. The compressor immediately came on and pumped up both sides to their previous levels, so that's all functioning properly. It just seems to pump up the right a little less than the left which does make me think it's a calibration issue.
Last edited by dannyzabolotny; 07-11-2016 at 05:31 PM.
1995 525i 5-speed - Thread
So I got INPA installed, it went pretty painlessly. Read all the car's modules, no errors or anything. Live stats are super cool too. I dunno why everybody makes INPA sound like a difficult thing to set up. I had the one click installer and a cable that I bought from BCable.com, worked out perfectly when combined with a 20-pin round adapter (my car is a 2000 so most things have to be done from that connector). I have NCSExpert, DIS, TIS, INPA, WinKFP, and a few more all set up.
Anyways, I found the self-leveling suspension settings, so I ran a few tests and confirmed that everything is functional. I'm still amazed at how I could raise and lower the suspension with just a button on an old laptop... makes me feel like I'm in the future (if 1999 was the future lol). I eventually found the function to adjust the ride height in the rear, and since I'm an idiot I went and overdid it, raising everything to monster truck heights haha. It is pretty level though, so it was definitely a calibration issue and not an air spring issue. Though I might still have to replace the air spring in the future since the older right air spring needs so many adjustments to be level. The values were already jacked up, probably from the shop that installed the new left air spring under the previous owner.
With a little more tweaking I think I can get it perfect. Thanks for all the advice, everybody!
1995 525i 5-speed - Thread
hang on hang on danny boy.
before you go over-adjusting w/ the INPA...
as other said - if it levels out when the door is opened, then its a leaky bag or hose.
but if it stays crooked once powered up....
before you overcompensate w/ the settings (which really shouldn't need tweaking all other things held constant...)...
get under and look at the ride height sensors. each rear control arm has a little sensor jobby on it. I'm guessing one of yours is bent or otherwise borked. you can clean up the connectors while you're there, hit them w/ some contact cleaner etc.
not uncommon for mechanics or road debris or whatever to wank one of those up a bit.
you can imagine if one of those is just a little screwed up and got banged around, that you'd rather fix it properly than compensate w/ software setting...
as I've said a million times its actually a pretty good system, simple, super easy to diagnose, and not that expensive to fix, short of the master pump unit going, and that only generally happens if the spare tire well fills up with water and swamps it. the overwhelming majority of problems lie with:
- leaky bags cracked from age
- bad sensor connections or joints
- less common, a leaky hose joint but even that seems to be only when a moron forks around with in an ill-advised attempt to fix it improperly
congrats on the Tour, and good luck, I bet you'll fix it in no times.
2003 M3CicM6 TiAg
2002 540iT Sport Vortech S/C 6MT LSD TiAg
2008 Audi A3 2.0T DSG (the daily beater)
2014 BMW X1 xDrive28i (wifemobile)
Former:
1985 MB Euro graymarket 300SL
1995.5 Audi S6 Avant (utility/winter billetturbobattlewagen)
Solid advice above to find the source but it doesn't appear there are any drawbacks to the quick INPA fix for a minor adjustment.
INPA is invaluable. It helped me to drill down and solve a unique data bus error throwing off several systems intermittently. Heat was causing a sketchy IHKA to cause suspension, key in ignition, ac compressor, and other errors. Swapped with a pulled part and 0 errors for a year now.
99 540iT - Merlot Truckster (TCG done 134k, might sell...)
00 528i/5 - Grüen Arrow (sold)
93 740i - Grün Hornet (sold)
00 740iL (R.I.P.)
I'll jack up the car and check the sensors later today to see if maybe there's some damage to them. The car level doesn't really change whether the car is on or off, so I don't think it's a leaky air spring. I almost never hear the compressor in normal driving, it rarely ever needs to do anything since the car just kinda stays at the same levels consistently.
1995 525i 5-speed - Thread
yep. when it's working properly it's nearly invisible and you never notice it being dynamic unless you really park on some weird surface or stick a 300lb table saw in the back (in which case it's pretty awesome how it levels out and the car drives great not dragging its ass...) everything you're saying says maybe it's just a dinged up sensor and everything else is working well, which is great news.
2003 M3CicM6 TiAg
2002 540iT Sport Vortech S/C 6MT LSD TiAg
2008 Audi A3 2.0T DSG (the daily beater)
2014 BMW X1 xDrive28i (wifemobile)
Former:
1985 MB Euro graymarket 300SL
1995.5 Audi S6 Avant (utility/winter billetturbobattlewagen)
GG is completely right...if there is a sensor or sensor linkage issue it could very well throw off the rear height settings. In that case, adjusting via INPA would be a bandaid to correcting the actual problem. Although, honestly I don't think correcting through INPA to compensate would have any ill effects. The proper repair would be to address any sensor/linkage issues first, then use ride height calibration as the icing on the cake...
Alvin Caragay
Mpire Automotive (https://www.facebook.com/MpireAutomotive/)
'96 AC Schnitzer S3 Sport CLS Replica (https://www.facebook.com/ACSS3SportCLSR)
'02 E39 540iAT
I did some more investigation last night, and I've determined that both sensors and sensor linkages are in good condition. Neither show any sign of damage or bending, so that's not the issue. I've also noticed that the sag has returned even after my adjustments. It's less than it was before, but it's still noticeable. I'm going to try and adjust it some more in INPA, but I think that means the right air spring is slowly failing because it's not staying up to the correct height.
1995 525i 5-speed - Thread
I usually check it my garage, but you're right, maybe my garage is a little slanted. When doing adjustments I checked with the measuring tape. I'll just throw the measuring tape into the glovebox and measure my car every now and then to see if it's actually sagging or not.
1995 525i 5-speed - Thread
I'll have to check that at some point. I don't see why it would slope in though, there's no water drain in the garage floor or anything like that.
1995 525i 5-speed - Thread
Bumping this as I, at this very moment, have the same issue. Passenger side is low like I set it, drivers side looks stock. I have my coding buddy who is also German looking at this issue on the German boards (bmw-syndikat.de). He just texted me a little update saying that SLS has service/assembly mode and a transport mode which can make things whacky. My car was on and off the lift for two weeks and the battery at some point died, it was fine yesterday but now is saggin. Perhaps it should have been in assembly mode for this work. We did the subframe bushings and rear control arms and ball joints, as well as exhaust work. I think my values might be all jacked now.
I am hoping Florian, my pal, can find some info from the German boards to help us both out, will relay. I am going to his house today after work to reset SLS and then try to even it out. He said he found a link for a beefed up air compressor available in Europe as well, interesting, will see what he comes up with.
My side to side delta is much more than it ever has been before.
Last edited by RSBBlackM3; 07-20-2016 at 02:36 PM.
BTW Even if the sensors and connectors are free and clean as Danny reports they could be dirty / worn inside causing this problem too. A way to test would be to jack the car, disconnect them, and measure resistance at both extremes then try to set an identical median position and measure that. If one pot is starting to crap out that could explain it being a bit off. You should also be able to read the position signal via inpa for such a test.
They aren't known for dying really btw but the cars are aging... Maybe now is when they all start to wear out...
2003 M3CicM6 TiAg
2002 540iT Sport Vortech S/C 6MT LSD TiAg
2008 Audi A3 2.0T DSG (the daily beater)
2014 BMW X1 xDrive28i (wifemobile)
Former:
1985 MB Euro graymarket 300SL
1995.5 Audi S6 Avant (utility/winter billetturbobattlewagen)
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