Rear air suspension issues

Liamkel · Post by **Liamkel** » Tue May 29, 2018 8:36 am

I've searched the forum and the Internet and can't seem to find a definitive answer to cover my problem. Last week my rear suspension dropped on both sides and wouldn't rises, then a couple of days later it would rise (I presumed airbags) but now it won't rise at all and it's been a few days now. I had a look at the air bags yesterday but with there being no air in them I struggled to check for leaks, I also stripped the under casing off and got to the compressor, no cable damage to the air feeds on either end but the compressor isn't doing anything. I started the car and it doesn't make a sound or vibrate or anything, it just shudders with the cars general engine vibrations. Should the compressor be making a noise?? I'm a relative newbie to mechanics, I have no problem in changing the air bags or compressor myself but don't know the indepth mechanics knowledge of what these working parts should be acting like. It seems to me maybe the airbags have gone and now the compressor has packed in as a result but don't want to jump the gun on buying and fitting a new compressor if you guys think there could be another possible answer. I've seen talk of the valve block which would make sense with both sides dropping at the same time, but i'm unsure. Any help will be appreciated so I can get any jobs done this weekend.

The cars a 58 plate, E70. Just hit 100k

Cheers

X5Sport · Post by **X5Sport** » Tue May 29, 2018 9:46 am

Check the compressor fuse is intact. It could be as simple as that. I can’t tell you the number for certain as I don’t have a fuse card for an E70 and my X6 doesn’t have air either.

If the compressor isn’t running and the air bags are empty that points towards that being at the centre of what is wrong.

This might help: Fuse Card piccie. It looks like fuses 37, 107 & 123 Based on the symbols

Liamkel · Post by **Liamkel** » Tue May 29, 2018 10:04 am

I checked the fuses, there all in tact. I checked both fuse boxes and all good. Wonder if that means it's not the compressor?

Thanks for the reply

Alan Gunn · Post by **Alan Gunn** » Tue May 29, 2018 10:30 am

Check the leveling sensors as well.
Pull the plugs of and spray some contact cleaner in then put them back on then off again to clean the contacts up.
Get a multi-meter and test for voltage to the pump as that could have faild in fact that might be the easiest to do so do that first.

Liamkel · Post by **Liamkel** » Tue May 29, 2018 11:25 am

I remember seeing the leveling sensor yesterday when I was poking around but didn't have a good look so i'll get some contact cleaner on them tommorrow. I'll also pick a volt meter up and check that, how do I test the voltage? And what should I be looking for.

Cheers

Liamkel · Post by **Liamkel** » Thu May 31, 2018 5:54 pm

Got the multimeter on the solenoid going into the compressor, I got a reading of 1.55 volts. Is this normal? The batteries reading 14 volts

Alan Gunn · Post by **Alan Gunn** » Fri Jun 01, 2018 12:20 pm

I would have thought it would be a lot higher but not sure with the can-bus system.
Somebody will have the correct answer soon i think.

Liamkel · Post by **Liamkel** » Mon Jun 18, 2018 4:27 am

Turns out my compressor had gone, got a new one on and the bags lifted and held. Compressor was £350 Inc vat for a OEM, plus 2 hours labour for the diagnosis and repair. The mechanics my neighbour and he spent alot of time on it trying to repair the compressor without having to replace it but had no luck, unfortunately for me. The compressor already on it was also a replacement, but not a OEM part.

AdamsX5 · Post by **AdamsX5** » Wed Oct 03, 2018 10:18 am

Can you tell when driving if the compressor or air bags have gone. Buying a car today and seems from pics the rears look very low. Is there any noise or warning something is wrong or a code being thrown up. What should I do to examine it??

Sent from my iPhone using Tapatalk

Alan Gunn · Post by **Alan Gunn** » Wed Oct 03, 2018 10:42 am

If it is very low look if it lifts when you start the car.
If it does then the bag is leaking.
Another thing might only be my car but if i park uneven ie 2 wheels on the curb and switch off and get out i here a noise sounds like the car is farting but it is the pump trying to level the car so i can here it working.
Hope that makes some sense to you.

AdamsX5 · Post by **AdamsX5** » Wed Oct 03, 2018 12:07 pm

[quote="Alan Gunn"]
If it is very low look if it lifts when you start the car.
If it does then the bag is leaking.
Another thing might only be my car but if i park uneven ie 2 wheels on the curb and switch off and get out i here a noise sounds like the car is farting but it is the pump trying to level the car so i can here it working.
Hope that makes some sense to you.
[/quote]
If it doesn’t lift does that mean either the pump or compressor has gone ??

Sent from my iPhone using Tapatalk

X5Sport · Post by **X5Sport** » Wed Oct 03, 2018 8:56 pm

Or the fuse.

In any event it could mean new bags or compressor (fuses don’t just blow). Bags are the most common issue.

AdamsX5 · Post by **AdamsX5** » Thu Oct 04, 2018 4:08 pm

[quote="X5Sport"]
Or the fuse.

In any event it could mean new bags or compressor (fuses don’t just blow). Bags are the most common issue.
[/quote]
I’m I right I’m assuming 5 seater has coils suspension and 7 seater air suspension??

Sent from my iPhone using Tapatalk

Alan Gunn · Post by **Alan Gunn** » Thu Oct 04, 2018 4:48 pm

My 5 seater has air at the rear but i thought they all did.

X5Sport · Post by **X5Sport** » Thu Oct 04, 2018 7:13 pm

Optional depending upon trim, though most have it. Use the last 7 of your VIN to get a build spec from somewhere like BMWvin dot com.

XSeries-forum

XSeries-forum