G31 air spring replacement help

[Billy_Whizzzz]

I think my rear spring needs replacement - there is an intermittent chassis warning fault that is non specific and can be traced (so dealer says) to right rear unit tho isn’t losing air and ride height looks fine. Chassis warning kicks in after 30 mins so of driving. I’ve bought a replacement Arnott rear spring (which of course main dealer won’t fit) and my local garage won’t either as they tell me it needs replacement calibrating after fitting and only dealer can do this. Is this right?

[helix403]

Anyone with dealer software or similar can set ride height.

[stevemcs]

I don't know about the G31, but on the E61/F11 you fit the spring, go into a sub menu (might be body control) recalibrate the system - it asks you heights then adjusts itself. So yes it does need calibrating and no you don't need factory diagnostics.

[Ed.Neumann]

You don't need to calibrate at all.

I undo the air line at the compressor and let all the air out.

Pull out the old spring.

Put in new one.

Fill with air with it jacked, important.

Then let the car down. It will self level.

[Ed.Neumann]

What year is the car?

I have seen that message more when the compressor can't let air out, usually because there is a small leak somewhere and the desiccant (sp?) is sucking in moisture and now too full to let the air pass through and allow the compressor to exhale air from the suspension.

Before swapping the spring I would try and put it on diagnostics and release all air from the springs, if the car does not go down you know it is the compressor.


To test the spring, simply don't use the car for 48 hours and see if it has sagged.

[Billy_Whizzzz]

Ed.Neumann said:

What year is the car?

I have seen that message more when the compressor can't let air out, usually because there is a small leak somewhere and the desiccant (sp?) is sucking in moisture and now too full to let the air pass through and allow the compressor to exhale air from the suspension.

Before swapping the spring I would try and put it on diagnostics and release all air from the springs, if the car does not go down you know it is the compressor.


To test the spring, simply don't use the car for 48 hours and see if it has sagged.

Thanks. Car is a ‘67 plate 530d x drive. Has been in twice to BMW and once to Indy and they’ve never managed to be specific re fault!!

[stevemcs]

You can also put it on a 2 poster, let the wheels drop then spray the airbags with soapy water and look for bubbles. They can sometimes self seal with how the springs fold over

[Ed.Neumann]

I was just about to say. Jack it up, wheel off and spray with some soapy water.

It is also an idea to jack up the side you think you have an issue with and leave it overnight, then lower it without unlocking and see if it sits low.

This again can get round the issue of the rubber on the spring folding over and sealing any split.

[Billy_Whizzzz]

Thanks all - BMW tell me the springs are fine as is compressor and only thing they can suggest is spending £5k to replace everything! Doesn’t seem to sag or lose air - just the annoying fault warning that pops up on every drive over 20 mins

[Ed.Neumann]

Sorry, they are talking absolute nonsense.

Buy a diagnostic machine and read the live data and codes.

Someone on the UK classifieds of F30 post is selling a laptop with the BMW software and cable for £150 I think it was.

I would just buy that, you will know within 20 minutes where the fault is.

[Ed.Neumann]

What is the actual chassis warning?

What was the code they read?