Door noise

[trueX5er]

Ocassionally, when I open the doors/trunk (usually previously locked) I hear a "phssstz" sound for about 1.5 seconds coming from the drivers-side rear of the vehicle. I know this is a normal sound, I just want to know what exactly it is, and if theres anyway to make it quieter or stop. It's not that it bugs me, but when I open the door to let my dog jump in, and it makes the noise, he gets all scared and frightened.
Any ideas?

[xx3]

I dunno about the E70, but thats where the BMW Nav computer would be on the E53 & E83. Maybe its turning on, reading the nav disk ?

[trueX5er]

nav disk is in the center console.
This is more of an air-getting-released noise.

[BL1]

I have heard the sound you mention on my X5.

I wondered whether it was a fuel pump or some such preparing the car to get ready to start....

[trueX5er]

so nobody knows?

[PatX]

I believe that it is a suspension thing getting primed. My wife's Cadillac STS makes the same sound. And, yes, it is definitely outside of the cabin.

[kicker]

i have had my x5 for 2 wks-it has been doing it from the start. i orginally thought it was a type of compartment decompression-due to how air tight the comcartpment is so you can shut the doors.(as is a mercedez/jag the windows drop so you can shut the doors). so i called the 800 # and they knew nothing about it. I called the service manager at the dealership and he said it is normal when you open the door it is the car waking up--and preparing itself for the start. I'm not sure, I buy that. but two night ago i heard a new sound, after an hours drive, parked in the garage-came in the house-after about 2 mins-went back into the garage-and heard humming or fan like sound (coming from the passanger rear wheel well) lasted about a min. Service manager said, going to sleeps sounds are also normal. And don't worry about it if unless it last longer than 30 min ????????????????????

[trueX5er]

huh...I still wanna know what that noise is !!
After a long drive, the fan running to cool everything down is normal. The sound should be coming from the grille, though....

[Fastbuck]

Originally Posted by BL1

I have heard the sound you mention on my X5.

I wondered whether it was a fuel pump or some such preparing the car to get ready to start....

I'm with you. That's certainly how it sounds. On the other hand, not too sure about BMW, but Mercedes use pneumatic locks. You could hear the pump re-energising after each open/lock.

[kicker]

So have anyone else heard these sounds ????