Hello everyone,

My 2014 BMW 525 Touring has rear self-levelling air suspension. Electrically and mechanically it seems to be working OK, but for the last week or so the rear of the car has been sinking right down to the lowest ride height overnight  (the bottom of the outer wheel arch is lower than the top of the tyre). If I start the car in the morning and leave it for a couple of minutes before driving off, the compressor runs and the suspension levels itself again pretty quickly. The car then rides normally and the body height looks fine for the rest of the day, even if I don't use the car. 

Measuring by sticking two fingers between the top of the tyre and the wheel arch, there's usually no discernable drop during the day (with the exception of Saturday, when it had dropped low by the evening). But, nearly every morning, it's dropped right down again (with the exception of two non-consecutive mornings, when it stayed level overnight). There are no warnings on the dashboard or iDrive about this at any time. The amount of drop is equal on both sides, indicating a common air leak.

I guess what I'm hoping is that someone will say "Oh yes - it's a common problem and it's always the solenoid valve" or something along those lines. I'm hoping it's not one of the suspension unit air bags, and am consoling myself with the thought that maybe a leak in the suspension unit would cause a drop on that side only (but logically I can't see why a leaking unit wouldn't cause air loss from the whole system anyway).

Has anyone else had this or a similar problem, and if so, how did you fix it?

Thanks!

Jon

 

Morning Jon

Welcome to the Forum

Definitely a leak somewhere it's a case of checking all the joints between the compressor and the air bags. I would start with the airbags as they are the most exposed part of the system and being rubber can perish and crack, their life will depend on the conditions they in everyday any where from 3 to 10years +

Dave

Thanks Dave. The car's on 80,000 miles so it's not surprising that they're going really - especially as we fairly regularly tow a caravan with it (though we haven't towed for a couple of months now). The bit I'm least looking forward to is getting the plastic underside panels off and back on! The rest looks comparatively easy, going by the YouTube videos I've seen. Can't find a video on removing the plastic under trim. I suppose I'll just have to start undoing bolts and see what comes loose.

Thanks again,

Jon

 

Morning Jon

Check www.realoem.com put the last 7 digits of your Vin in the search box it will bring up your model, then check the suspension/body sections to find what your looking for.

There are small exploded drawings that will help seeing what goes where and what the fastners are any plastic fastners I wouls buy replacements before starting work. This will guarantee none break !! (sods law at work) and if they are brittle and break you have replacements.

Check www.pelicanparts.com it is and American site so you won't find any diesels but the petrol versions are virtually the same underneath, they have some very comprehensive "How Too's" with pictures 

Dave

F11 Jon,

hello Jon, I have exactly the same issue with both sides going down overnight, hence please confirm if you now know the cause or causes?

 

thanks,

 

Larry

 

 

Morning Larry

Welcome to the Forum

Check for leaks starting with the Airbags then the pipe work in the Boot the is an air distribution valve that also has an exhaust capability so check all connections and its operation.

Dave