strange noise before start
 

My car is 2009 3.5d. At random time, the car produce some noise as soon as I open the door before I start the car after overnight, from underneath the car, and last about 1 or 2 mins. I can't tell where exactly:yikes:

Here is the video:
https://www.youtube.com/watch?v=OZhLZdFsIHg

The only thing I can guess is the air pump is doing inflation, but noise is not from the rear of the car. Can someone tell where this noise is from? Would this represent some premature failure? of the air pump?

Thanks

:thumbup: 100% correct. The noise is from your compressor...which as it happens, is situated under the vehicle pretty much below the front seat.

If it is an ongoing thing (happens every morning you unlock the car) then it's a 99% chance your rear air springs have perished to some extent. Get them swapped out sooner rather than later.

I don't have the air suspension and my X5 makes a noise as soon as I unlock it or open the door. I don't think it lasts quite as long as the noise in the video, so yours might be something different. I believe in my case, it might be a fuel pump priming.

If it is equipped with the third row seating option then it has rear self-leveling suspension...if not then I'm not qualified to say. Good catch Xtony, I'd hate to be leading the OP up the garden path because I never checked my facts.

Thanks guys. My car does have the 3rd row seats. The noise just last a few mins.

It happens maybe once in a few weeks. My question is, is this noise too loud or is it normal? If I change to a new air compressor, is it supposed to be less loud? I don't know if other people's e70 has the same behavior like this or not.

Another question is, it typically happens on a morning, after overnight cool down, why is car doing self-leveling at this time? Is this normal?

My experience was very similar (I too have 3rd row seating). It started pretty gradually with compressor engaging after an extended period of inactivity, typically overnight. Over a period of roughly 3 months it got progressively more frequent until at a stage it became very apparent that there was an air leak. As for the noise level, it sounds pretty standard on the video but that doesn't mean much I guess. From what I understand, if the compressor becomes noisy there is no doubting that there is something wrong since this is almost always as a result of a collapsed bearing (service technician's words, not mine). If you want to check for a potential leak it is very easy to do yourself although at the early stages of failure I believe it can be difficult to pinpoint.
It may help to mention that I was informed by an air spring supplier that the typical lifespan of an air spring is roughly 80-120 thousand kilometers.

Thanks mart_dev. My car is 81k km now.

How to check if air bag is leaking, as you are saying it's easy?

What parts have you replaced at the end? Air compressor and air bags?

What will the car behave after replacement of the air spring? Will the car run the air compressor only once in a few months?

Read Mujihads thread entitled REAR AIR SUSPENSION PROGRAMING near the bottom of the first page.

OP, I urge you to take care of this right away. I had the exact same noise a couple months ago and my compressor went out while I was driving on the highway two weeks after I first started noticing the noise. This caused the rear to completely collapse and the ride was terrible and extremely bouncy/difficult to control.

The dealer recommended I change the compressor only but I went ahead and changed both the compressor and air bags as the bags have never been replaced and were only an extra $400 from my dealer. The compressor was $1100 FYI. If you were looking a lower cost option (noticed you're in Canada) you can go with Arnott. I copied the links below. The DIY was extremely easy and only basic tools are required. It took me about an hour to do with the help of my wife to guide the air springs into their slot. They also show a video on the installation for your reference.

Springs: http://www.arnottindustries.com/part...98_gid911.html
Compressor: http://www.arnottindustries.com/part...8_gid1042.html

If I may interject. Don't replace the compressor on the suspicion it may be faulty. Have a qualified technician take a listen to it first. It's neither cheap, nor is it considered to be a consumable, unlike the air springs which are ultimately going to fail at some point it every vehicle's life time. Much like conventional shocks need replacing. In the video you provided the sound seems to me to resemble any small, 12v air compressor (much like the ones most of us keep in the trunk of our vehicles for routine tire pressure correction). Unless it's running rough I wouldn't throw money at it. Like I said, get a professional to take a listen first. But definitely, don't leave it unattended.

One last thing, your compressor runs whenever it needs to correct the ride height of your vehicle. For example, if you load up the whole family and the kitchen sink, the compressor adds air to compensate for the extra weight. When you all climb out the vehicle will obviously raise up which activates the solenoid in the valve block and air is expelled, bringing the vehicle back to a level setting. This all typically happens every day without most of us even noticing.
And by the way, I replaced both rear air springs (Arnotts are the only way to go) and my compressor is still in tip top condition. I stripped it and the valve block to check because that's just in my nature but ultimately wasted 2 hours of my life I'll never get back. It really is a pretty simple 12v air compressor albeit of the high duty cycle variety.

Thanks guys. By now I read many posts about symptoms and DIYs of rear self-leveling suspension. Now I'm clear that's the issue.

Like I mentioned earlier, it only happens once in a few weeks, and I can't tell by eyes that my car rear is lowered or having uneven heights between left and right, before I open the door to see it does inflation.
Or my car's air springs only leaks in a very small degree?

I do prefer the preventative fixes, but I doubt the behavior of the car will still be the same after I replace the air springs...

ART-qitec, after you replaced the parts, do you no longer hear that loud compression noise anymore?

Yes the car was silent after that. I agree with Mart_dev in that a lot of compressors do sound that way but I've spoken with numerous BMW mechanics about it and they all say that the compressor in our cars shouldn't be audible...in fact they say the compressor starts making that sound when it's starting to go out. But like Mart_dev said, don't throw parts at the car first...just see a mechanic as soon as possible, when my compressor went out the car was extremely dangerous to drive. It would almost lose control every time I drove over a pothole.

Also if it is in fact your compressor, the sound would be coming from under the bottom of your car right below the passenger side door. Best of luck to you, let me know if you have any other questions.

I used to have EXACT same noise (including the airy "whoosh" at the end) for several seconds regularly after a drive. Since the vehicle was new.

Always wondered what it was, and even brought it up to the SA. She told me it's something to do with emisions. I am pretty sure it was just a dumb answer to get me off her back.

I am not sure it's a suspension compressor though..

Oh, I too have the one at the end, but it's different from the one that occurs when I wake the car up. The one at the end is the system that pumps fuel vapors so they can be pumped into the engine and burned when the engine is running again.

I do notice there are different kinds of sound, every time after driving and parked car, but I have to be close to the car and listen intentionally. I thought that's maybe from some mechanic, or some pumps, to finish the things up. So this matches what ART-qitec said about 'spoken with numerous BMW mechanics about sound shouldn't be audible' and what mart_dev mentioned compressor is acting everyday.


My air springs are not leaking too fast to drug the compressor to death too soon, so I guess I can wait for Xmas time to see if Arnotts would be on sale :)

Well, thank you for answering my question then! :)

fyi never take your vehicle to BMW OF MANHATTAN there are theft they will take parts from your vehicle and replace other people bad parts
oil was leaking from valve cover,i take it to bmw of Manhattan for replace, i endup with multiple problem like check engine light and coolants leaking. when i take it back they reset the fault which is evap,3 day after the chk light came back on when i scan it ssme evap i take it back ,they told me thst the purge valve bad,they replace it.3 day after the light came back on when i scan it ,the same evap i take it back and also told them about the coolants leak again they reset the evap code and told me thst my water pump is leaking,i had replace the waterpump before i take it in and notice that the hose us leaking but they insisted that the pump is leaking,i went and take my vehicle back since then the chk light on same evap and water pump will run every time i unlock the vehicle and will run when turn off the engine every time it run it will run for about 10-15 min now wnen it run it will kill the battery if any got the answer what cause the wter pump to run when i open the door i will greatly appreciate. thank you

1. BMW of Manhattan is notorious, even legendarily, bad.

2. How do you know the WATER pump is running??????

3. Did you know this thread is 4 years old?

Welcome!

i can see the coolant circulating in the expansion tank, is there a fix for this its a 2012 bmw x5

rupe start a new thread. your problem has nothing to do with the air bag compressor.