What's that air sound when I open the doors?

[CLCX5]

When I open the doors sometimes (generally the first time I enter the car after it's been driven) there is a loud mechanical air sound almost like what I'd expect if the car was lowering somehow, but nothing that I can see happens when it does it. So what's going on when it makes that sound?

[opasha]

Originally Posted by CLCX5

When I open the doors sometimes (generally the first time I enter the car after it's been driven) there is a loud mechanical air sound almost like what I'd expect if the car was lowering somehow, but nothing that I can see happens when it does it. So what's going on when it makes that sound?

It's your ECU. The same occurs when you hook up your OBD2 with your laptop for coding. It's all normal.

[Doanster]

Whoa??? ECU? That doesn't make sense, unless you're saying it's some sort of cooling fan for the ECU.
Totally sounds like the rear end is raising or lowering, as CLCX said.
I know it's normal and am not concerned, but curious as to what it really is.

[opasha]

Originally Posted by Doanster

Whoa??? ECU? That doesn't make sense, unless you're saying it's some sort of cooling fan for the ECU.
Totally sounds like the rear end is raising or lowering, as CLCX said.
I know it's normal and am not concerned, but curious as to what it really is.

It's not the rear end raising/lowering because I have stock suspension, and I hear this sound too randomly upon door opening and always when I connect to the OBD2 port. It's something within the car's "computer/brain".

[Dash52]

Fuel pump priming.

[opasha]

Originally Posted by Dash52

Fuel pump priming.

Maybe. I think I might have heard this sound before also whenever I popped my hood, but I don't remember.

[Heden]

Is it not the side bolsters deflating in the comfort seats? There are several reports from members mentioning this.

[MattBianco]

In a different car, I get this and it is from the air suspension exhaust. It is a quick whoosh and it is triggered by touching the handle bar (keyless) to open a door.

[CLCX5]

Originally Posted by Heden

Is it not the side bolsters deflating in the comfort seats? There are several reports from members mentioning this.

It sounds to me more like it's under and to the rear of the car rather than inside? But I really don't know!

[opasha]

Originally Posted by Heden

Is it not the side bolsters deflating in the comfort seats? There are several reports from members mentioning this.

I have MC seats, and it has nothing to do with this. The sound comes from the engine area, but it could be the suspension doing something (even if it is stock).

[CLCX5]

Originally Posted by MattBianco

In a different car, I get this and it is from the air suspension exhaust. It is a quick whoosh and it is triggered by touching the handle bar (keyless) to open a door.

Yes, it's a bit like when a roller coaster rolls into the loading area and let's out a loud airy pssssssssshh sound. And that's when it happens, right when pulling the handle.

[MattBianco]

@CLCX5, I don't drive the X5 more than once a week, and have not noticed.

I am betting it is the suspension. The other car is an MB and has a different keyless system; I can trigger the sound by merely touching the door handle without pulling it on the MB.

[Dash52]

You are hearing the fuel pump. End of story.

When you unlock the car, or open the door, the car is "waking up". It runs the fuel pump for about 2 seconds to prime the system, anticipating you starting the engine. It is 100% normal.

/thread
BMW Level 1 Master Technician

[Doanster]

Thanks Dash! Master Tech, eh? Now we know who to ping for all of our future problems. Muahahahaha...

[Dash52]

Originally Posted by Doanster

Thanks Dash! Master Tech, eh? Now we know who to ping for all of our future problems. Muahahahaha...

Actually, just quoting from original thread.....did the research, found the answer from an expert.

[opasha]

Originally Posted by Dash52

You are hearing the fuel pump. End of story.

When you unlock the car, or open the door, the car is "waking up". It runs the fuel pump for about 2 seconds to prime the system, anticipating you starting the engine. It is 100% normal.

/thread
BMW Level 1 Master Technician

Good find. That makes more sense .

[CLCX5]

Thanks, Dash52!