BimmerFest BMW Forum banner

1 - 16 of 16 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
Hi
My 2014 F15 developed air suspension problems that manifests as both air springs lowering all the way down, but only from time to time. When the car starts, it pumps it back up, stays like that for few days, a week ,and then it happens again. Discovered that when I engage or disengage the parking brake , it instantly starts raising the car! looks like it's somehow connected!
Any thoughts?
went to see BMW authorised service, they had no clue of what's going on.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #2 ·
Also, worth mentioning is that it's a 7-seater, so 3 rows of seats, only rear air suspension. Engaging the parking brake deflates the suspension., and after few minutes start the car, disengage the parking brake and the suspension inflates back!
 

·
Registered
Joined
·
948 Posts
I'd be curious if your F15 airbags are simply shot, and if disengagement of the parking brake is merely signaling some hard-coded program logic of a "ready to drive" mode that makes final auto-leveling kick in. I don't know that such a thing is true, but I could imagine that your bags are simply leaking all night, and then they're re-inflating because you've started the car and are you're about to drive. They're about the right age to be replaced.

This guy explains our system really well.


I assume I'll be replacing both of my bags in 2-3 years, and you're about that far ahead of me. Honestly, they're just fancy kickball balls. Not much to them. After several years, they leak.

If they are leaking, you'll kill your compressor and its desiccant next. So maybe think about replacement as preventative maintenance and/or troubleshooting. You can check 'em with soapy water. There's a ton of E70 knowledge out there.
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #4 ·
I'd be curious if your F15 airbags are simply shot, and if disengagement of the parking brake is merely signaling some hard-coded program logic of a "ready to drive" mode that makes final auto-leveling kick in. I don't know that such a thing is true, but I could imagine that your bags are simply leaking all night, and then they're re-inflating because you've started the car and are you're about to drive. They're about the right age to be replaced.

This guy explains our system really well.


I assume I'll be replacing both of my bags in 2-3 years, and you're about that far ahead of me. Honestly, they're just fancy kickball balls. Not much to them. After several years, they leak.

If they are leaking, you'll kill your compressor and its desiccant next. So maybe think about replacement as preventative maintenance and/or troubleshooting. You can check 'em with soapy water. There's a ton of E70 knowledge out there.
Thanks a lot!
I read a lot of posts on this forum.... haven't found anything similar to my case....
Funny thing; system never detects any error , even when driving the car on "empty" shocks!
From my amateur point of view one thing is sure; definitely tied to park.brake circuit, once down, only thing that brings the car up is when fiddling with the brake; as soon as you release it the car raises instantly!
 

·
Registered
Joined
·
948 Posts
My understanding is that it's a nearly closed system by design. So the little compressor unit dries out just a tiny bit of ambient air with a chemical desiccant chamber, and then crushes the dried air into your air ride system. That makes up for a small amount of intentional bleed.

But if you have an UNintentional amount of bleed from the air bladders themselves, then the little compressor (and its little desiccant chamber) aren't nearly of a suitable size to keep up with "kickball balls" that are fundamentally leaking. The compressor unit will start to pop fuses and will eventually just fail. So then you'll have three things to replace (compressor unit and two air bags).

Occam's razor: the simplest explanation is usually true. Your two air-ride bladders are reaching their life expectancy, if they're factory OE units and were manufactured 2012-2014. It's like replacing shocks, belts, or windshield wipers. They're just rubber things.

Could it be some weird short or grounding error on the bus? Could it be a defect in the switches? Could the sensors be seized on both sides? Sure. But I'd start with the obvious, likely problem. At a minimum, start with diagnosing whether the bags are any good now.
 

·
Registered
Joined
·
1,279 Posts
This happens to me once in a while. After starting, it'll go back to normal, and it'll be ok for many weeks. One time i discovered it after 3 days of not driving it. One time it was just overnight. But at other times, it's all ok even after 3 days.

I thought it was because i was playing with the Eco switch... was in Eco mode (softest mode, Adaptive M) after returning home.... and then it slowly sinks later.

Both sides go down the same time (not one side only). Is this related to the air bags or the compressor (or that switch)? Or just tighten the air hose's nut?
 

·
Registered
Joined
·
3,680 Posts
The airbags fail about every 80,000 miles or so give or take. I’d bet your bags are shot. Not a compressor issue. Not related to the parking brake. Many look for other issues to justify it deflating but it turns out to be just the bag. The bags will fail. If you are near 80,000 miles, I would think you are, replace the bags. Couple hours DIY. Done. Deflated bags won’t cause a fault code. Deflating bags while driving will.


Sent from my iPhone using Bimmerfest
 

·
Registered
Joined
·
1,279 Posts
They dealer just brought over the X5 back to the office (like ordering food... free delivery lol). They picked it up this morning for an oil change/etc regular maintenance. Their technician looked at the suspension's airbags since i mentioned it to the SA earlier. They said it's still fine. I have almost 47k miles on it. It's about $1600 parts/labor to replace it these airbags (less if we DIY it). The OE bags cost a fortune but the aftermarket ones are half or a quarter the price.
 

·
Registered
Joined
·
3,680 Posts
They dealer just brought over the X5 back to the office (like ordering food... free delivery lol). They picked it up this morning for an oil change/etc regular maintenance. Their technician looked at the suspension's airbags since i mentioned it to the SA earlier. They said it's still fine. I have almost 47k miles on it. It's about $1600 parts/labor to replace it these airbags (less if we DIY it). The OE bags cost a fortune but the aftermarket ones are half or a quarter the price.
Bags should be about $150 each. Both sides can be replaced in 1-2 hours DIY. Small holes near where the bag folds over itself can give intermittent failures. Anyone who replaces them needs to read the directions that come with it first. The bolt is designed to not need removing or tightening when installing the air pipe. I have seen someone also install them without locking in the top part of the bag. POP! The SAV also needs to be supported on both sides when the bags are inflating after installation.


Sent from my iPhone using Bimmerfest mobile app
 

·
Registered
Joined
·
1,279 Posts
..... The bolt is designed to not need removing or tightening when installing the air pipe. ...
In case I don't have that same or appropriate instructions with the new aftermarket bags, may I know which bolt are you referring to here? Do you have a picture or from somebody's picture on this bolt/location that i should not remove/tighten? Thanks.
 

·
Registered
Joined
·
631 Posts
So 6 years old, rear air bag replacement is not abnormal. There is a lot of factors on how long an air bag will last on our BMW's. If you take a look at the air bag construction, there is a potential to pick up something from the road that get stuck within the "fold" of the air bag...and puncture your bag....a very, very, very small hole. This can happen any time...

Depending on your environment, the rubber may deteriorate quicker than for other F15/F85 owners.....

I highly recommend Arnott brand over BMW.....unless you need to keep BMW parts on your car....the $20-$30 different isn't much, but the Arnott bag hold up longer...not sure if the bag thickness is thicker or not......didn't measure them.
 

·
Registered
Joined
·
3,680 Posts
In case I don't have that same or appropriate instructions with the new aftermarket bags, may I know which bolt are you referring to here? Do you have a picture or from somebody's picture on this bolt/location that i should not remove/tighten? Thanks.
Sorry. More like the “locking nut” on the bag itself. The air pipes have a groove about a cm in from the end. The air bag locking nut has the ability to accept this groove and never have to be tightened. It’s in the instructions.


Sent from my iPhone using Bimmerfest mobile app
 

·
Registered
Joined
·
1,279 Posts
So 6 years old, rear air bag replacement is not abnormal. There is a lot of factors on how long an air bag will last on our BMW's. If you take a look at the air bag construction, there is a potential to pick up something from the road that get stuck within the "fold" of the air bag...and puncture your bag....a very, very, very small hole. This can happen any time...

Depending on your environment, the rubber may deteriorate quicker than for other F15/F85 owners.....

I highly recommend Arnott brand over BMW.....unless you need to keep BMW parts on your car....the $20-$30 different isn't much, but the Arnott bag hold up longer...not sure if the bag thickness is thicker or not......didn't measure them.
May i know what is the Arnott p/n that you use on an X5 F15? I was looking at some on ebay/amazon and the Arnott ones did not show the cover/umbrella-thing - do we reuse this exterior cover/umbrella thing from the old unit or it doesn't fit? Thanks


edit: i just found the Arnott website 2016 BMW X5 (F15 Chassis) and it says the A-2642 (before this i saw 2 different part numbers, one being this A-2642).
 

·
Registered
Joined
·
1,279 Posts
I changed mine 8 days ago. So far it doesn't squat anymore! The first side took 4 hours (lots of things to unplug, etc) and the second side about 38 minutes lol. The most difficult part indeed is unhooking the bottom side of the bag (clips) from the suspension's arm. After misusing half a dozen tools unsuccessfully, I finally found a 10" adjustable pliers (the one with a 45-degree head) and this is the must-have tool to do it.
 
1 - 16 of 16 Posts
Top