Self levelling suspension
 

I have 30d 2009 which has 7 seats.

We often park the car on the kerb outide our house and you can see and hear the car lower & raise. Recently after the car was parked on the kerb I moved it to our drive and when I got in the car in the morning the car was still low on one side but as soon as I started engine it raised (and stayed raised for days)

Over the past few days I’ve parked the car on the same kerb and noticed it’s not lowering. There are no error messages being reported.

The question I have is under what criteria does the self levelling suspension work? Is it based on weight in the car? Angle of kerb?

I checked in the manual pg 86 and just talks about error codes.

Thanks in advance.

The self-lveling suspension should not noticeable 'raise and lower' at times. As you add weight to the car, it will basically counter the loading to maintain a set height.

HOWEVER, when one of the airbags gets a pinhole leak in one of the folds, air can leak out. Park it on a kerb (or curb...;) ) and it may leak down overnight- then noticeably pump up in the AM.

As the airbags move around in their mounts, it is possible for a leak to come and go, so it doesnt do it all the time.

But you most likely need to replace the airbags. Pretty cheap, 30 minute job- easy. Search for DIYs and posts about it. US$150 for parts? as I recall

My guess...I dont have it on mine.

+1 -

If your rear suspensions lowers itself overnight or after a few days parked, is likely that you have an air leak (in the Suspension Airbags). Mine experienced this issue, it was a relatively easy job and parts were not expensive.

It took a bit of finesse to the airbags back and there are a couple of steps you need to take to deflate them and to get it back up --search for the procedure--

I remember someone told me is better to replace the airbag as soon as you experience leaks as the compressor will need to work more and that is an expensive part to replace.

Thanks for the replies & advice so far.. I've been quoted £250 per corner by an independent garage. I've just watched the video's and I'm wondering if it's something I can do..

Is it normal for it to be sitting like this on the kerb/curb? :)

http://webmail.kelcs.co.uk/x5/IMG_8179.JPG

http://webmail.kelcs.co.uk/x5/IMG_8180.JPG

http://webmail.kelcs.co.uk/x5/IMG_8181.JPG

Parts are around $275 USD for both bags -

I used these https://www.amazon.com/Pair-Arnott-R..._&dpSrc=detail

And took me around 2 hours in total, including the removal of each rear wheel, could be done way faster but I just took my time. It really depends on how handy you are and the time you have to do it.

Wow, you pay a lot less for these than we do in the UK, cheapest I can find is £195 EACH!

I've found what the ride heights should be and currently I'm within tolerance so will keep an eye on the suspension.

https://workshop-manuals.com/bmw/x_s...de_height_e70/

One other thing you may want to consider...

Parking that way and causing the compressor to run 'often' could be a concern as it may cause life of the compressor to be considerably shortened.

When there's a leak and it doesn't get fixed/is ignored (not the case here it seems), the compressor can burn itself out from overuse and they are much more expensive than the bags. Very easy to replace, but $$$.

If by 'often' you mean on a daily basis or something similar, you may want to reconsider.

Lol

When you come back in a few months with a burned out compressor saying 'well it doesn't rise any more', it will be I-told-you-so.

The car WILL drive the airbags to meet those tolerances- burning out the compressor in the process.

There are cheaper places to buy them, you just aren't looking hard enough. IMO. It's an easy DIY. Many posts.

Thanks for all the feedback.

Is it recommended to replace both sides at the same time?

Yes. I'd recommend the same for any suspension component.