air release sound from car
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'07 s550 4matic
air release sound from car
I have a 03 e500...lately Ive noticed a strange noise. I hear a humming noise while driving at moderate speeds and the sound builds up while Im driving. Once I slow down or stop completely, the humming sound stops and I hear a very noticeable air release sound from the front of the car. It sounds like the air brakes on a truck. ANy idea what this is? Could it be the SBC or maybe the airmatic suspension? The dealer wasnt able to find anything wrong.
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BMW E30. I've turned to the dark side.
its the airmatic suspension releasing air. some noise is normal but its possible the release line may have popped out of the chamber in the front bumper that helps quiet the noise. if it happens often, like every time you come to a stop, there may be something else wrong.
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'07 s550 4matic
Originally Posted by benz-tech
its the airmatic suspension releasing air. some noise is normal but its possible the release line may have popped out of the chamber in the front bumper that helps quiet the noise. if it happens often, like every time you come to a stop, there may be something else wrong.
thanks for the tip. So its most likely not the SBC then correct? I hear the sound on about half of my stops. I also hear it once in awhile while driving, usually right when i start slowing down
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BMW E30. I've turned to the dark side.
there are other noises associated w/ SBC. one occasional noise is during pressure buildup on the SBC pump. park the car, turn the car off and start pumping the brake pedal, you will hear/feal the pressure pump turn on. if that is the same sound and the sound/vibration bothers you, there is a small modification that any dealer can perform by putting a damper in the fill line. HTH
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'07 s550 4matic
Originally Posted by benz-tech
there are other noises associated w/ SBC. one occasional noise is during pressure buildup on the SBC pump. park the car, turn the car off and start pumping the brake pedal, you will hear/feal the pressure pump turn on. if that is the same sound and the sound/vibration bothers you, there is a small modification that any dealer can perform by putting a damper in the fill line. HTH
its definitely not the same vibration/sound I get from pumping the brake. This sound is very noticeable humming noise that constantly builds up and gets louder as I drive and then stops with a "PSSSHH" air burst noise when I brake or slow down..similar to the air brake on a truck. The sound is loud enough to where people in the next car can hear it. I feel like I'm driving a semi-truck.
Last edited by hotwiredbenz; Jan 1, 2006 at 02:57 PM.
Thread Starter
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'07 s550 4matic
figured out it def is the airmatic. Once I hear the howling sound, pressing the reaise car button eliminates the sound and I immediately hear the air release noise. So this is most likely just a release line loose? The pump isnt faulty right?
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Thread Starter
Senior Member
Joined: Sep 2005
Posts: 281
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'07 s550 4matic
I have taken it to several places and nobody has been able to find anything wrong with the car. Though they have been able to hear the sound.
I am 100% sure though it has something to do with the airmatic
I am 100% sure though it has something to do with the airmatic
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