[qb530d]

Hi all.

I've just changed from my old E39 530d to a 2015 F11 530d Touring. A month into ownership, the rear suspension is misbehaving on the F11 like so many others.

My 2015 F11 has done about 50k miles.
It's got an Arnott air spring on the left, OEM on the right.
I just bought an Arnott air spring for the right, I figure it's only a matter of time before it needs replacing even if it's ok a the moment (I think it is, no sounds of air leaking).
Suspension deflated a few days ago - my wife was driving, she wasn't watching for when it deflated.
I drove the car after it had been parked for a few hours and the air suspension re-inflated to normal height.
It stayed up for 4 days until I drove it.
I got out to get something out of the boot then noticed it had deflated completely down to the bump stops again.
I can hear the compressor running for periods then it stops, suspension doesn't inflate, car remains on the bump stops.

So I strongly suspect compressor discharge valve.

A few questions on this:

1) Does anyone know where to source a genuine Wabco replacement discharge solenoid valve? Or a known high quality replacement? Always a bit wary of cheap ones on ebay.

2) I also found that 4x4airseals sell an air compressor piston seal & air dryer filtration repair seal kit for it BMW 5 7 Series F01 F02 F04 F07 GT F11 Air compressor Piston seal & Air Dryer Filtration Repair Kit - 4x4 Air Seals. Has anyone had success using one of these kits?

3) From what I read, one of the problem is the filter and pipe for the incoming air either getting detached or damaged so water gets in. Apparently the air intake is behind the wheel arch liner or bumper? Anyone know about this or know for sure which side that's on before I start taking things apart? Or replaced their filter?

4) I saw in this post, someone made an adapter and pumped up the car manually while it calls for air and the valves are open. Has anyone done this?

Seems rubbish, so many failing either because of air springs, compressors or both at such low mileage. My old E39 didn't do this until an air spring leaked at 120k miles!

Thanks.

 

[Johnnyroper]

If I recall correctly when I fitted my towbar on previous f11 the air intake is behind bumper on drivers side.

 

[qb530d]

If I recall correctly when I fitted my towbar on previous f11 the air intake is behind bumper on drivers side.

Ah that's great, thanks

 

[qb530d]

Update: I decided to pull apart the compressor after watching this video where he finds the dryer granules are very wet:

It didn't take too long to get it off, I was even able to with the suspension fully deflated. I found mine were in a similar state to the ones on the video, very wet. So I careful dried them and the filters with a combination of microwaving on very low power (90W) and a warm air boot dryer that I have. I had less corrosion in the valve highlighted in the video.

I tested the discharge solenoid valve like DiagnoseDan did in this video by applying 12V to it:

Just like in that video, my solenoid valve wasn't moving when power applied. I gave it a tap and sprayed brake cleaner into it then tried again and it started clicking, intermittently at first then after repeating, it would activate reliably for 60 or so repetitions.

So I have put it back together and the suspension returned to normal height so I'm still interested in answers to those questions at the beginning of the thread, especially where to buy a replacement Wabco discharge solenoid valve.

 

[qb530d]

If I recall correctly when I fitted my towbar on previous f11 the air intake is behind bumper on drivers side.

Update: I followed the pipe and it looks like it goes to the left side of the car - passenger side for UK RHD cars

 

[qb530d]

Can't seem to find a genuine Wabco solenoid vent valve anywhere. Anyone else found one?

 

[Johnnyroper]

Update: I followed the pipe and it looks like it goes to the left side of the car - passenger side for UK RHD cars

Strange as I remember mine being cable tied to the bumper crash bar as it had an inline filter on end,sure it was drivers side.

 

[qb530d]

So I bought one of the solenoid valves off ebay. The main larger o-ring is very thin and slightly too large. Also, it draws 0.8A compared to the Wabco one which is rated at 1.6A so makes me wonder whether it's really up to the high pressure of the air suspension, and I don't have a way to pressure test it. Doesn't inspire confidence tbh. Starting to feeling forced into buying a whole new compressor because neither BMW nor Wabco will sell the solenoid valve separately. How bad is that? And what a total and utter waste of an otherwise good compressor. If anyone has any advice on this, I'd be grateful.