X5 Rear Air Suspension

[zaw]

Newbie to the Forum

Recently Purchased an X5 3.0D SE 2004 all seems to be running fine. However I have noted what I believe to be the Air pump compressor kick in quite frequently particularly on start up and subsequent driving

I guess its possible there is a slight air leak, I have been reading and Air Springs can leak, however I have not noticed any noticeable  ride height drop

I am a little concerned that since the compressor is kicking in frequently if there is a leak then it may cause the compressor to over work.

However there are period it does go off, but I would say it does run frequently as well. There may also be times when it is working at a faster rate and then slows but that may be due to the fact its compensated for the leak.

I have heard that leveling sensors can be faulty as well as air springs.

1. What is the most likely cause/s

2. I have a few interdependent BMW specialist nearby I imagine they would be able to diagnose this?

3. What would the cost be to fit new air springs

Any advice would be appreciated

Thanks

[Horizon]

Hi and welcome to the forum, there is a coil spring retro fit kit for the E53, you can get it off EBay, it's less than £200. This will replace the airbags and do away with the need for a compressor and level sensors, you can turn the error message of on the dash with a scanner 1.4.0.
Or new air bags are around £. 150 each you might need to book your X in at a local indie to diagnose the  leak or fault if you can't find it yourself.

[zaw]

Thank you

[Steamyrotter]

first place i would check is the 2 connections below the boot floor to the right of the spare wheel.
There are a blue and red pipe entering a black through block
Check each side with a little soapy water to see if leak is there..

These have been known to leak, and I had one pop off a while ago..

[Ubatoid]

Arnott air bags are around £200 pair delivered direct from the States. 3 day delivery when I bought mine!. Most likely cause.Failing that its the valves or unions. You can easily check all connectors and pipework and bags with soapy water - apply plenty and watch for growing bubbles. Im told the valves can be repaired with new O rings, I will find out this weekend as I plan to look at mine as it drops overnight. For me springs are a non starter.

[zaw]

Hello

Thanks for the advice, i only bought the car a few weeks ago and was in the process of switching over from my E34 , I could not see any visible height drop overnight.
One would expect that this would be the period that is least compensated for in respect of air being pumped into it the air system.
However surprisingly the compressor has not come on at all today and I have been driving most of the day the ride height seems totally correct so a little confusing.
Anyway unless the compressor has packed up another few days like that I would be a happy bunny,

Could a faulty sensor have been causing the compressor to pump and if so does the system purely rely on sensors and does it not have a method to detect when the air system is fully pumped up.

What happens to excess air that a sensor may encourage the air system to reach does it release it at a certain pressure.

Thanks

[zaw]

Sorry Ubatoid

Another question can you easily visually detect your ride height drops or do you always have a cue s the compressor kicks in and how frequently does yours kick in.

Thanks

[Ubatoid]

It's not a very sophisticated system. It just pumps or vents until it is at the right hight as indicated by the sensors. Mine drops noticeably sometimes other times not. But the pump always runs after being left for a while. I'll post up a picture story on the How to thread at the weekend after I've looked at the valves- assuming I've got the correct size o rings in my kit.

[zaw]

Hello.

Further to this I left it as had recently bought the car to monitor it over the next few weeks and discovered the air pump compressor does not kick in at all some days even when left overnight.

I also noted that it definately appears to kick in more often when the temperature outside drops so wonder if that affects the sensors as cant see how that would effect air leaks.

Any ideas?

Thank you

[X5Sport]

I had no leaks on mine and the compressor did not run that often, nor did the car drop even if left for several days (or longer).

Cold weather may cause the air pressure in the bag to drop a bit which might trigger the compressor to act?

Richard

[zaw]

Hello.

The car doesn't show any noticeable drop and like I said the compressor seems to kick in cold weather you could have a point if it causes the pressure to drop. Perhaps some compressors a little noisy than others as well. So hence I can hear it more often if it was quieter I might not.

Thanks

[mojamusic]

my e53 4.6is rear air suspension was lowering almost every night (both sides). as soon as i opened the car, the compressor would pump the air bags back up so i rode it this way for about a year. as both sides deflated at the same time, it would be logical the leak was somewhere from the pump to the airbags. instead of spraying the air bags and connections with soapy water, i went ahead and purchased both airbags and had my local mechanic install them. luckily, it was my air bags which were both leaking. the old ones had many little stress cracks in the flexible rubber shell, which may have cracked all the way through? the car now rides better, more stable from the rear. the whole job cost $630 as opposed to $2700 from the dealership. i bought the airbags from BMW south atlanta for $180 a side and $70 total shipping. my mechanic took 2.5 hours and charged me $200. i prefer to buy genuine BMW if affordable. arnott makes oem replacements but offered a comfort and sport model. the 4.6is uses the sport model. the price was so similar, i went with genuine. i'm glad i replaced the air shocks.

[Chrisw4266]

Where abouts are you bud? I've got bmw scanner and DIS can plug it in for you if needed.

[PhilUK]

[quote="Horizon"]
Hi and welcome to the forum, there is a coil spring retro fit kit for the E53, you can get it off EBay, it's less than £200. This will replace the airbags and do away with the need for a compressor and level sensors, you can turn the error message of on the dash with a scanner 1.4.0.
Or new air bags are around £. 150 each you might need to book your X in at a local indie to diagnose the  leak or fault if you can't find it yourself.
[/quote]

Here you go: http://www.ebay.co.uk/itm/261375521862?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649