Buzzing noise
#1
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Probably an obvious answer out there, but I'm curious........ I've got an '05 CS. When I open the driver's door after the car has been sitting for approx. 20 mins or more, I hear a buzzing sound comig from underneath the car.
It sounds like a small motor or pump.
Any ideas?
Thanks in advance.
Scott
It sounds like a small motor or pump.
Any ideas?
Thanks in advance.
Scott
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The fuel pump is audible, when the driver's door is first opened, prior to starting.
The air pump, under the passenger's seat, kicks on, as required, with the vehicle running, to build pressure for the air suspension. It may be that the excessive operation means that there is a leak requiring correction.
The air pump, under the passenger's seat, kicks on, as required, with the vehicle running, to build pressure for the air suspension. It may be that the excessive operation means that there is a leak requiring correction.
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Thanks guys.
The car has PASM.
The pitch of the buzzing is much lower than that of a fuel pump and comes from the driver's seat area.
It does not run continuously...... Just for about 1.5 seconds when I open the driver's door.
Is the 1.5 second burst normal for PASM cars? If it helps, I don't notice any odd settling of the suspension when parked on flat surfaces.
Thanks again.
The car has PASM.
The pitch of the buzzing is much lower than that of a fuel pump and comes from the driver's seat area.
It does not run continuously...... Just for about 1.5 seconds when I open the driver's door.
Is the 1.5 second burst normal for PASM cars? If it helps, I don't notice any odd settling of the suspension when parked on flat surfaces.
Thanks again.
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Originally Posted by Scott C
CPM? Don't know the acronym.
The nav dvd activates when you open the door and you can hear it spinning......it is under the front right seat...may be what you are hearing.
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Originally Posted by philg3
It's the fuel pump to allow the engine to start quickly.
I checked it empirically by having the wife open the door while I lay underneath the car. The noise eminated from the fuel tank.
Additionally, I found it in my Service Information Technik Manual (WKD488-910) in Section 2, page 9.
Originally Posted by Service Information Techik Manual
When the driver's door is first opened, the signal from the door contact switch (via CAN) is additionally used to briefly activate the fuel pump. Fuel pressure is already built up before the engine is started.
This is normal operation for the system.
Good call Phil!
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Originally Posted by wingless
The fuel pump is audible, when the driver's door is first opened, prior to starting.
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Man, there are a bunch of sensitive types on here.
*(Puts on best tuxedo and Oscar acceptance voice)*
I'd like to thank, in order of response, the following:
1. Henna Gaijin
2. Wingless
3. Philg3
A special mention should go to ltc as I'm sure he is critiquing the design that requires a "priming" of the pump.
![thumbup](https://rennlist.com/forums/graemlins/thumbup.gif)
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
Seriously, thanks guys
*(Puts on best tuxedo and Oscar acceptance voice)*
I'd like to thank, in order of response, the following:
1. Henna Gaijin
2. Wingless
3. Philg3
A special mention should go to ltc as I'm sure he is critiquing the design that requires a "priming" of the pump.
![thumbup](https://rennlist.com/forums/graemlins/thumbup.gif)
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
Seriously, thanks guys
![thumbsup](https://rennlist.com/forums/graemlins/bigok.gif)