[Dazcush]

Hi guys, looking for some advice or info if anyone has previous experience with this issue:

So the rear suspension was completely dropped on my 2014 BMW f11 touring and I was doing some research online about what to do. I took out the compressor and checked everything which was working fine. The fuse in the back was blown as the compressor wasn't turning off. The problem turned out to be a simple fix - replacing the relay for the compressor!

Since then, a chassis warning message regularly pops up saying to "continue at a moderate speed and have the problem checked by service". It does not come up every time I turn the car on, but usually when I add weight to the car (fill the gas tank, suitcases in the back or mtb bikes on the roof, etc.

I am wondering is there any sensors knocked or affected when the suspension dropped (it was like this for over a week until I got the problem sorted) or could there be something else causing the problem?

Any help would be greatly appreciated as it would cost a great deal to bring it to a BMW dealership to have it looked at!

Cheers,
Darragh

[Casspian]

Hi Darragh, did you manage to get it fixed? I started getting the same message a few months ago. It started with the rear self-leveling suspension in my F11 sagging. After technician connected it to a computer for diagnosis (and i presume re-set fault codes), it returned to normal height. However, the error message persisted - pops up each time ignition is on. I also noticed that the ride is much more jittery/uncomfortable than before (despite suspension being on normal height, as much as possible to visually assess). I also noticed that sometimes (even when ignition is off) the compressor works and it looks like the rear suspension is rising slightly.
My mechanic suspects the compressor, relay or even car batter (which on 2013 manufactured 141 registered has not been replaced as far as I know). He's getting quotes for parts, but I have a feeling this is not an easy fix.

Any insights welcome.

[Dazcush]

Originally Posted by Casspian

Hi Darragh, did you manage to get it fixed? I started getting the same message a few months ago. It started with the rear self-leveling suspension in my F11 sagging. After technician connected it to a computer for diagnosis (and i presume re-set fault codes), it returned to normal height. However, the error message persisted - pops up each time ignition is on. I also noticed that the ride is much more jittery/uncomfortable than before (despite suspension being on normal height, as much as possible to visually assess). I also noticed that sometimes (even when ignition is off) the compressor works and it looks like the rear suspension is rising slightly.
My mechanic suspects the compressor, relay or even car batter (which on 2013 manufactured 141 registered has not been replaced as far as I know). He's getting quotes for parts, but I have a feeling this is not an easy fix.

Any insights welcome.

Hi Casspian

Turns out it was a simple fix. Solenoid needed a replacement and that solved the issue. There was an issue with it which kept the compressor continuously going and blowing the fuse.

Hope this helps. Let me know how you get on.

[Casspian]

Hi Dazcush, All

I got a solenoid, but my mechanic didn't want to install (quoting if he dis-assembles - there is a risk that washers/seals will disintegrate, and it is difficult to get them, BMW doesn't sell them, and I'll be without a car for a few weeks, fair point). He recommended Aerosus compressor, which I bought.
The install of the compressor cleared the codes. My mechanic also said that I should replace the air springs, as they had micro damages, and the compressor worked every 5-10 minutes for that reason (and was very loud - see below) - which makes the compressor work harder and the compressor will fail faster again. I got Aerosus air springs - so far so good, but not happy with Aerosus compressor.

Problem - Aerosus compressor is very loud. While error message on the dashboard was cleared, but it is very audible inside the car, even when driving with quiet music on. Really very loud, to the extent that it makes it pointless to drive a nice bmw. The new rear airprings make the compressor work less frequent (typically when switching then engine on and occasionally during the drive), but it is annoying. I got another Aerousus compressor, but it was equally loud. (my mechanic, independent BMW specialist, told me he fitted many aerosus compressors into BMW F11s, the first time he heard one so loud).

In my F01 730d I had the same error message (as in the picture up in the thread), so I tried Arnott (purchased from Trodo, they had good reviews on Trustpilot). Installed it today, and the mechanic said it is very quiet, as should be (cost about the same as Aerosus, though it appears Aerosus has permanent discounts). So I'm very happy with Arnott, and I don't recommend Aerosus compressors (Aerosus springs appear to be fine).

The other thing that annoys me in F11, apologies for digressing, is that it is very uncomfortable (the rear suspension in particular, especially when going through speed bumps/ramps, potholes, drain covers, etc). The suspension is not sagging, but the ride quality is terrible, and I think it wasn't the case before. To be fair, I noticed it long before the compressor issues, so nothing to do with Aerosus/Arnott, but still annoying. About 2 years ago I replaced the shock absorbers in all 4 corners at around 160k km (decent Sachs shocks, which I believe is OEM), but that shouldn't negatively impact comfort. The new air springs from Aerosus to replace leaking ones didn't improve comfort. And the cars is by the way on 245/45 R18 non-run flat Michelin all-season, so quite small wheels with a lot of good rubber, should be comfortable. My wife drives the F11, and she also confirms she thinks the ride comfort deteriorated.

Concluding:
- I recommend Arnott compressor vs Aerosus
- if anyone has any ideas why F11 rear suspension is uncomfortable (despite new airsprings, compressor, shocks, and non-funflat tyes on small alloys), do let us know.